Opinion by
Me. Justice Roberts,On January 8, 1971, a pharmacist and his assistant were beaten and robbed by three unidentified males on Germantown Avenue in Philadelphia at approximately 8:00 p.m. Almost six weeks later the police received an anonymous phone call from a youth who said that one of the participants in that robbery was named “Primo” and that “Primo” lived in a certain area of Philadelphia. Two days later, appellant, George Betrand, a juvenile, known to the police as “Primo”, was arrested without a warrant. He was taken immediately to the station house and placed in a locked interrogation room where he remained for approximately two hours. A detective subsequently arrived and advised him of his rights by reading from the standard police interrogation card. After approximately one-half hour of questioning, appellant gave an oral statement admitting his involvement in the robbery.
Appellant was charged with robbery, assault with intent to kill, aggravated assault and battery, and conspiracy. He was adjudicated delinquent by the Juvenile Division of the Family Court of Philadelphia and committed to the Youth Development Center, South. Following that determination he appealed to the Superior Court which affirmed the adjudication of delinquency. Betrand Appeal, 222 Pa. Superior Ct. 67, 293 A. 2d 359 (1972) (Packel, J., dissenting, joined by Hoffman, Spaulding, JJ.) We granted allocatur. Appellant contends that his confession was the fruit of an illegal arrest and was also the product of an involuntary and unintelligent waiver of his Fifth Amendment right against self incrimination.1 We reverse and remand.
*385At this late date it is uncontrovertibly beyond dispute that the Constitution of the United States prohibits the arrest of a person unless the arresting officer has probable cause to believe that a crime has been or is being committed. McCray v. Illinois, 386 U.S. 300, 87 S. Ct. 1056 (1967); Ker v. California, 374 U.S. 23, 83 S. Ct. 1623 (1963); Henry v. United States, 361 U.S. 98, 80 S. Ct. 168 (1959); Carroll v. United States, 267 U.S. 132, 45 S. Ct. 280 (1925); Commonwealth v. Goslee, 427 Pa. 403, 234 A. 2d 849 (1967); Commonwealth v. Ellsworth, 421 Pa. 169, 218 A. 2d 249 (1966); Commonwealth v. Bosurgi, 411 Pa. 56, 190 A. 2d 304 (1963). Probable cause has repeatedly been held to exist only “where ‘the facts and circumstances within their [the officers’] knowledge and of which they had reasonably trustworthy information [are] sufficient in themselves to warrant a man of reasonable caution in the belief that ‘an offense has been or is being committed’.” Brinegar v. United States, 338 U.S. 160, 175-76, 69 S. Ct. 1302, 1311 (1949), quoting Carroll v. United States, supra at 162, 45 S. Ct. at 288; see McCray v. Illinois, supra; Ker v. California, supra; Commonwealth v. Goslee, supra; Commonwealth v. Ellsworth, supra. See also Commonwealth ex rel. Grano v. Anderson, 446 P. 2d 272, 273 ( 3d Cir. 1971).2
It is also well settled that even hearsay information is sometimes sufficient to establish probable cause. See Draper v. United States, 358 U.S. 307, 79 S. Ct. 329 (1959); Brinegar v. United States, supra. However, *386when, as here, probable cause for a warrantless arrest3 is based on such hearsay information supplied by an anonymous informer, the arresting officer must have two types of additional information before probable cause is established. First, in order to assure that the tip is not merely an unsupported rumor, the officer must know the underlying circumstances from which the informer concluded that the suspect participated in the robbery. Second, in order to reduce the possibility that a tip meeting the first standard is merely a well-constructed fabrication, the officer must have some reasonable basis for concluding that the source of the tip was reliable. Spinelli v. United States, 393 U.S. 410, 89 S. Ct. 584 (1969); Aguilar v. Texas, 378 U.S. 108, 84 S. Ct. 1509 (1964); Commonwealth v. Garvin, 448 Pa. 258, 293 A. 2d 33 (1972); cf. Commonwealth v. Mamon, 449 Pa. 249, 297 A. 2d 471 (1972).
Applying the Aguilar-Spinelli standards here it is patently clear that the informant’s tip, the sole basis for appellant’s arrest, was insufficient to establish probable cause. First, the tip came from an unidentified informant, who supplied no indication that he had any personal knowledge of the crime whatsoever. His information was completely conclusory with no underlying facts or circumstances to bolster his report. The anonymous caller merely told the police that the suspect’s name was “Primo” and indicated where “Primo” lived—nothing more. Thus the first requirement of Agmlar-Spinelli—underlying circumstances supporting an informant’s conclusion—was clearly absent here.4
*387Secondly, as appellant succinctly points out “the record is devoid of underlying circumstances showing [any] reason to believe that the informant himself was a credible person.” Thus the second aspect of the Aguilar-Bpinelli test is likewise unfulfilled.
The Commonwealth urges that probable cause was established here because the “anonymous telephone call contained significant inner indicia of reliability, important details of which were corroborated by the arresting officers’ own knowledge.” Apparently the Commonwealth is contending that the informant was inherently reliable since he was an “anonymous citizen-informant” who was “too scared” to reveal his identity to the police. Such an informant, argues the Commonwealth, is more reliable than “the typical stoolie”. However, the Commonwealth here engages in sheer conjecture, as it admittedly has no evidence that the unknown informant was either a “typical stoolie” or a “citizen-informant”. It thus has absolutely no indication of the informant’s reliability.
Next the Commonwealth contends that the tip was corroborated because the officers knew that “Primo” was a gang member and that he lived near the scene of the robbery. However, such information is certainly not sufficient independent corroboration, but simply the grossest form of unsupported speculation and guilt by association.
A similar disingenuous argument by the Commonwealth was categorically rejected by this Court in Commonwealth v. Goslee, supra. There the Commonwealth argued it had probable cause to arrest appellant for *388burglary because he was a known burglar and lived near the scene of the crime. This Court held that such information at best amounted to mere suspicion. We there said that “[t]o sustain this conviction we would be forced to countenance a proposition that presence plus a prior conviction is sufficient for arrest—a proposition we cannot accept.” Commonwealth v. Goslee, supra at 407, 234 A. 2d at 851. See Commonwealth v. One 1958 Plymouth Sedan, 418 Pa. 457, 211 A. 2d 536 (1965).
Thus this record reveals only an anonymous, unsubstantiated tip, knowledge that the suspect was a gang member, and that he lived near the scene of the robbery. This is clearly constitutionally insufficient to establish probable cause and the arrest was therefore illegal. Commonwealth v. Holton, 432 Pa. 11, 247 A. 2d 228 (1968).
The next question to be resolved is whether appellant’s oral statement was so tainted by the illegal arrest as to be inadmissible. The seminal case on this issue is Wong Sun v. United States, 371 U.S. 471, 488, 83 S. Ct. 407, 417 (1963), where the Supreme Court announced that the relevant test is: “. . . ‘whether, granting establishment of the primary illegality, the evidence to which instant objection is made has been come at by exploitation of that illegality or instead by means sufficiently distinguishable to be purged of the primary taint.’” (Citation omitted.) See Commonwealth v. Cephas, 447 Pa. 500, 291 A. 2d 106 (1972); Commonwealth v. Rowe, 445 Pa. 454, 282 A. 2d 319 (1971).
The Supreme Court also noted that the challenged evidence may be purged of the primary taint only (1) if it results from “ ‘an intervening independent act of a free will,’ ” Wong Sun, supra at 486, 83 S. Ct. at 416, or (2) if the connection between the arrest and the evidence (confession) has “ ‘become so attenuated as to *389dissipate the taint.’ ” Id. at 491, 83 S. Ct. at 419 (citation omitted).
In Commonwealth ex rel. Craig v. Maroney, 348 F. 2d 22, 29 (3d Cir. 1965), cert. denied, 384 U.S. 1019, 86 S. Ct. 1966 (1966), the Third Circuit noted two specific factors of major significance in determining the relationship between an illegal arrest and subsequent confession:
“(a) the proximity of an initial illegal custodial act to the procurement of the confession; and
“(b) the intervention of other circumstances subsequent to an illegal arrest which provide a cause so unrelated to that initial illegality that the acquired evidence may not reasonably be said to have been directly derived from, and thereby tainted by, that illegal arrest.”
This Court, in Commonwealth v. Bishop, 425 Pa. 175, 183, 228 A. 2d 661, 666, cert. denied, 389 U.S. 875, 88 S. Ct. 168 (1967), subsequently explained the Wong Sun test this way: “[I]f the connection between the arrest and the confession is shown to be so vague or tenuous ‘as to dissipate the taint’ or ‘sufficiently an act of free will,’ the confession is admissible, despite the illegality of the arrest. By ‘sufficiently an act of free will,’ we mean that not only was the confession truly voluntary, but also free of any element of coerciveness due to the unlawful arrest. The burden of proof, of course, is upon the Commonwealth.” (Footnote omitted.)
It should also be noted that once the primary illegality—here the illegal arrest—is established, the burden is on the Commonwealth to establish that the confession has been come at “by means sufficiently distinguishable to be purged of the primary taint” rather than “by exploitation of that illegality.” See United States v. Wade, 388 U.S. 218, 239-40, 87 S. Ct. 1926, *3901939 (1967); Commonwealth v. Bishop, supra at 183, 228 A. 2d at 666.
Applying the above tests appellant’s statement was clearly come at through exploitation of and tainted by the illegal arrest. As the dissenters in the Superior Court noted “the proximity between the illegal arrest and appellant’s statement was extremely close—within one or two hours.” Betrand Appeal, supra at 71, 293 A. 2d at 361. The detective in charge of the case admitted that he instructed the arresting officers to arrest appellant on the street, a place where appellant was unlikely to be in the company of a parent or other adult to advise him. Appellant was in fact arrested on a Philadelphia street and transported to detective headquarters. As previously noted appellant was immediately locked in an interrogation room in a cell block and left there alone for between one and two hours. A police detective then arrived and advised appellant of his rights by reading from the standard police interrogation card. Approximately one-half hour later, appellant admitted his involvement in the robbery.
In these circumstances where there Avas not a break in the chain of events, a definite causal connection between the illegal arrest and the subsequent confession obviously did exist. See Commonwealth v. Bishop, supra at 182, 228 A. 2d at 665.
The Commonwealth argues, however, that advising appellant of his Miranda rights constituted “a cause so unrelated to that initial illegality that the acquired evidence may not reasonably be said to have been directly derived from, and thereby tainted by, that illegal arrest.” In essence the Commonwealth contends that although the arrest may have been illegal, advising appellant of his Miranda rights was an “intervening independent act” which purged appellant’s subsequent alleged waiver of those rights and his confession from the taint of the illegal arrest. However, the mere perfune*391tory recital of Miranda warnings to appellant is insufficient to break the chain of events leading directly from the illegal arrest to the confession. Commonwealth v. Brown, 451 Pa. 395, 301 A. 2d 876 (1973) ; see United States v. Kilgen, 431 F. 2d 627, 632 (5th Cir. 1970), modified on other grounds, 445 F. 2d 287 (1971). Numerous courts have held that an illegal arrest, ipso facto, is sufficient to exclude any subsequently obtained evidence as tainted fruit. United States v. Kilgen, supra; Collins v. Beto, 348 F. 2d 823, 829 ( 5th Cir. 1965); Gatlin v. United States, 326 F. 2d 666, 672 (D.C. Cir. 1963); United States v. Ricci, 313 F. Supp. 31, 34 (E.D. Pa. 1970); People v. Weaver, 35 Mich. App. 504, 192 N.W. 2d 572 (1971). Thus it is difficult to understand how the recital of Miranda warnings can dissipate that taint.
This Court specifically stated in Commonwealth v. Bishop, supra at 183, 228 A. 2d at 666, that in order for an independent act of free will to dissipate the taint not only must it be truly voluntary “but also free of any element of coerciveness due to the unlawful arrest.” Here that “element of coerciveness” produced by the illegal arrest and an immediate two-hour incommunicado detention was not dissipated by the bare reading of Miranda warnings from a card.
Such a conclusion, as that urged by the Commonwealth, would lead to the anomalous and clearly impermissible result that the police could illegally arrest suspects at will knowing that by merely reciting Miranda warnings to those suspects they could purge any subsequent confessions of the taint of the initial illegality. As the Fifth Circuit stated: “Such a . . . [result] would practically eviscerate the prophylactic effect of the exclusionary rule. Moreover, if a mere showing that a confession during a period of unlawful detention was Voluntary’ were sufficient to establish its admissibility, Wong Sun would be an empty promise, for the *392inadmissibility of ‘involuntary’ confessions has long been fully recognized.” Collins v. Beto, supra at 829. Surely the Miranda warning, intended to deter exploitive police practices, cannot now be perverted to thwart the equally important deterrent purpose behind the exclusionary rule of Wong Sun.
The Commonwealth having failed to meet its burden of proving that appellant’s confession was purged of the taint of the initial illegal arrest, appellant’s confession was inadmissible.
The order of the Superior Court is reversed, and the matter remanded to the court of original jurisdiction for proceedings consistent with this opinion.
Mr. Chief Justice Jones and Mr. Justice Eagen concurred in the result.Because we hold today that appellant’s confession was inextricably tainted by the illegal arrest, and thus inadmissible, we need not reach appellant’s related contention that his waiver of his Fifth Amendment rights was involuntary.
In Orano, the Third Circuit noted that probable cause depends upon two criteria:
(1) a belief that the offense has been committed;
(2) sufficient basis for a finding of probable cause that the party under suspicion committed the offense charged. 446 F. 2d 272, 273 (3d Cir. 1971). See generally Note, The United States Courts of Appeals: 1971-1972 Term Criminal Law and Procedure, 61 Geo. U. J. 280, 805 (1972).
Since the police may not make a warrantless arrest unless the facts within their knowledge would justify the issuance of a valid warrant, Whitely v. Warden, 401 U.S. 560, 91 S. Ct. 1031 (1971); McCray v. Illinois, 386 U.S. 300, 87 S. Ct. 1056 (1967), then a fortiori probable cause for the issuance of a warrant must be identical to probable cause to make a warrantless arrest.
The Supreme Court cautioned in Spmelli that a tip may very weU be a casual rumor circulating in the underworld or an accu*387sation based merely on an individual’s reputation. 393 U.S. 410, 416, 89 S. Gt. 584, 589 (1969). Moreover, as appellant perceptively suggests “[i]t would not be unrealistic or even unreasonable to think that casual rumors such as the one at issue here are plentiful in the Philadelphia gang milieu, and are even a convenient way for rival gang members to satisfy a grudge.”