I concur in the views expressed in the opinion prepared by Mr. Justice Traynor but wish to add^ some additional views which are pertinent to the issue here involved.
The issue presented is whether there is any competent evidence of probable cause on which to hold defendant to answer. If there is no such evidence the writ of prohibition must issue. (Rogers v. Superior Court, 46 Cal.2d 3 [291 P.2d 929]; Badillo v. Superior Court, 46 Cal.2d 269 [294 P.2d 23] ; People v. Valenti, 49 Cal.2d 199 [316 P.2d 633].) Narcotics seized during the arrest and subsequent search of defendant’s person and premises was the sole evidence offered to show probable cause. This evidence is admissible only if the arrest and search by the police officers was legal. (People v. Cahan, 44 Cal.2d 434 [282 P.2d 905].) Defendant challenged the legality of the arrest and seizure, pointing out that there was no warrant, and contending that the police officers acted without probable cause. In these circumstances the burden is on the prosecution to justify the officers’ conduct. (Badillo v. Superior Court, supra, 46 Cal.2d at 272.) Thus, whether defendant can be held to answer, as well as the issuance or denial of the writ of prohibition, hinges on proof of the same fact, namely did the police officers act with probable cause.
*821The police officers testified that they had received information from two reliable informants that defendant was in possession of narcotics. This was the only evidence offered to establish that the police officers had probable cause, and thus it forms the sole basis on which the arrest and search can be justified. On cross-examination defendant sought to elicit the names of the informants. The magistrate denied defendant the right to cross-examine on such matter, ruling that the identity of the informants was confidential and' privileged.
Conceding that this testimony is sufficient to establish probable cause to make an arrest and search, nevertheless the denial of defendant’s right to cross-examine the prosecution witnesses regarding the identity of informants renders it incompetent. The result being that the search and seizure is illegal, which renders the evidence seized inadmissible under the exclusionary rule, and leaves the court without any competent evidence of probable cause to hold defendant to answer.
The People contend that the magistrate properly refused to disclose the identity of the informants for the reason that such matter is privileged under section 1881, subdivision 5, of the Code of Civil Procedure. This section provides: “A public officer cannot be examined as to communications made to him in official confidence, when the public interest would suffer by the disclosure.” It is argued that if the identity of informants must be disclosed this flow of information to police officers will break an important link in law enforcement, causing the public to suffer.
For the reasons stated below I have concluded that the privilege asserted by the People must yield in the present circumstances to the greater interest of protecting an accused’s constitutional right to a fair hearing.
“The purpose of the preliminary hearing is to weed out groundless or unsupported charges of grave offenses, and to relieve the accused of the degradation and the expense of a criminal trial.” (Jaffe v. Stone, 18 Cal.2d 146, 150 [114 P.2d 335, 135 A.L.R. 775].) To accomplish this purpose the Legislature has prescribed the procedure to be followed. In essence this procedure is a carbon copy of the minimum requirements and safeguards which are required to be used in criminal trials pursuant to article I, section 13 of the California Constitution. An accused at a preliminary hearing is entitled to counsel (Pen. Code, § 859), examination and cross-*822examination of witnesses (Pen. Code, §§ 865, 866) and the traditional rights of an accused at a criminal trial (Pen. Code. § 866.5). To state the obvious, orderly procedures based on the concept of fair play provide the means by which the purpose of a preliminary hearing is'to be accomplished. (See People v. Brooks, 72 Cal.App.2d 657, 661 [165 P.2d 51].)
The right to cross-examination, which is basic to our judicial system and has been from earliest times, is part of this fundamental right available to an accused. (People v. Ramistella, 306 N.Y. 379 [118 N.E.2d 566]; see Alford v. United States, 282 U.S. 687 [51 S.Ct. 218, 75 L.Ed. 624] ; People v. Cole, 43 N.Y. 508, 512-513.) An improper denial of the right of cross-examination constitutes a denial of due process (Argonaut Ins. Exchange v. Industrial Acc. Com., 120 Cal.App.2d 145, 152, 153 [260 P.2d 817] ; Columbia-Geneva Steel Div., U.S. Steel Co. v. Industrial Acc. Com., 115 Cal.App.2d 862, 865 [253 P.2d 45] ; Langendorf United Bakeries v. Industrial Acc. Com., 87 Cal.App.2d 103, 104-105 [195 P.2d 887].) Apart from historical considerations the reason cross-examination is one of the ingredients of a fair hearing is practical. In a trial or preliminary hearing there is usually a disputed factual issue. Where this occurs, cross-examination provides a major method for establishing the accuracy and reliability of direct testimony. The method of cross-examination is necessary since experience tells us that ex parte statements are too uncertain and unreliable to be considered in the investigation of controverted facts. (People v. McGowan, 80 Cal.App. 293, 298-299 [251 P. 643] ; People v. Seitz, 100 Cal.App. 113, 119 [279 P. 1070]; see People v. Cole, supra, 43 N.Y. at 512-513.)
A violation of these fundamental rights at a preliminary hearing results in a deprivation of due process of law. (See People v. Napthaly, 105 Cal. 641, 644 [39 P. 29]; People v. Salas, 80 Cal.App. 318 [250 P. 526] ; People v. Miller, 123 Cal.App. 499 [11 P.2d 884].)
Not every instance in which a cross-examiner’s question is disallowed will defendant’s right to a fair hearing be abridged, since the matter may be too unimportant (Naylor v. Ashton, 20 Cal.App. 544 [130 P. 181]), or there may be no prejudice (People v. Burch, 46 Cal.App. 391 [189 P. 716]), or the question may involve issues which can be brought up at a more appropriate time (Mitchell v. Excelsior Water & Min. Co., 41 Cal.App. 240 [182 P. 326]). However, where the subject of cross-examination concerns the matter at issue there *823can be no doubt that the refusal to permit such question results in a denial of a fair hearing. (People v. Manchetti, 29 Cal.2d 452, 459 [175 P.2d 533]; People v. McGowan, supra, 80 Cal.App. at 296-299; Langendorf United Bakeries v. Industrial Acc. Com., supra, 87 Cal.App.2d at 104-105; Columbia-Geneva Steel Div., U.S. Steel Co. v. Industrial Acc. Com., supra, 115 Cal.App.2d at 865; Argonaut Ins. Exchange v. Industrial Acc. Com., supra, 120 Cal.App.2d at 152, 153.)
Such, principle applies to the ease at bar. As heretofore pointed out the only evidence to show probable cause that defendant had committed a felony was evidence seized by the police officers. This evidence is only admissible if the search was legal (People v. Cahan, supra, 44 Cal.2d 434). In an attempt to show the search was legal the prosecution witnesses testified that they were acting on the information of a reliable informant. This was the sole evidence offered by the prosecution to prove the legality of the search. Defendant can only rebut this evidence by either showing that the informant does not exist, that he is unreliable, or that the information conveyed to the police officers was otherwise than that testified to. But the opportunity to establish any one of these alternatives depends on knowledge of the informant’s identity. To deny defendant this opportunity is to hold him to answer on the basis of ex parte statements, which we know from experience are too unreliable to be considered as evidence where factual issues are disputed.
The words of Mr. Justice Douglas dissenting in United States v. Nugent, 346 U.S. 1 at 13 [73 S.Ct. 991, 97 L.Ed. 1417], echo the unfairness of such a denial. “The use of statements by informers who need not confront the person under investigation or accusation has such an infamous history that it should be rooted out from our procedure. A hearing at which these faceless people are allowed to present their whispered rumors and yet escape the test and torture of cross-examination is not a hearing in the Anglo-American sense.”
Thus, the choice was with the prosecution; they could elect to claim the privilege of not disclosing the informants’ identity, and have the evidence on direct examination stricken, or save this direct testimony by revealing the name of the informants. In this case they chose to rely on the privilege. Under these circumstances the testimony of the police officers, who refused to submit to cross-examination, is to be stricken from the record. (People v. Manchetti, supra, 29 Cal.2d at *824459-462; People v. McGowan, supra, 80 Cal.App. at 296, 297; People v. Seitz, supra, 100 Cal.App. at 119, Code Civ. Proc., §§ 1846, 2048; see People v. Ochoa, 118 Cal.App.2d 566, 568-569 [258 P.2d 104] ; McCormick on Evidence, § 19; 5 Wigmore on Evidence (3d ed.) § 1391, p. 112.)
Therefore, there is no competent evidence of probable cause before the magistrate and the writ of prohibition must be granted.