*476OPINION OF THE COURT BY
LUM, C.J.Defendant-appellant Wendell Amaya Pichay (appellant) appeals from his convictions for Unauthorized Control of a Propelled Vehicle, in violation of Hawaii Revised Statutes (HRS) § 708-836; Possession of a Prohibited Firearm, in violation of HRS § 134 — 8; and for keeping a Firearm in a Prohibited Place, in violation of HRS § 134 — 6. Appellant argues that the trial court erred in denying appellant a new trial after the court, over objections by both the State and defensé counsel, granted the jury’s request to take two dolls and a calculator in the jury room on the second day of deliberations. Finding that appellant’s constitutional right to a fair trial has been denied, we vacate the conviction and remand for a new trial.
I.
The pertinent facts are undisputed. The jury retired on the morning of May 21,1990. Still without a verdict on May 22,1990 at 8:30 a.m., the jury sent a communication to the court requesting permission to use two dolls and a calculator apparently brought in by a juror that morning. The court granted permission to the jury at 8:55 a.m. over objections by the State and the defense. The jury returned guilty verdicts to all counts later that morning and was discharged without examination to determine whether they used the extraneous materials; if so, how they used them; and whether the use had a prejudicial effect on their verdict. The court allowed a record of the objections to be made several days after the verdict, at which time appellant moved for a mistrial and a new trial. This appeal followed.
II.
“A fair trial by an impartial jury is guaranteed to the criminally accused by both the sixth amendment of the United States *477Constitution and article I, § 14 of the Hawaii Constitution. Inherent in this requirement is that the jury be free from outside influences.” State v. Williamson, 72 Haw. 97, 102, 807 P.2d 593, 596 (1991); State v. Keliiholokai, 58 Haw. 356, 569 P.2d 891 (1977).
It is undisputed on appeal that it was error to allow the jury to consider non-evidentiary materials during deliberations. See, e.g., Southwick v. Ace Auto Body Shop, Inc., 646 S.W.2d 401, 404 (Mo. App. 1983) (“ ‘[I]t is improper and erroneous to allow the jury to have articles not properly in evidence which would tend to influence the verdict’ ”); Walker v. Sparkling Pools, Inc., 171 So. 2d 205 (Fla. App. 1965) (holding it was reversible error to permit the jury to take a mechanical jack, not introduced into evidence, into the jury room). See also State v. Keliiholokai, 58 Haw. at 358, 569 P.2d at 893-94 (“jury’s verdict must be based upon evidence received in open court and not from outside sources”); Lyon v. Bush, 49 Haw. 116, 124, 412 P.2d 662, 667 (1966) (quoting Public Operating Corp. v. Weingart, 257 App. Div. 379, 13 N.Y.S.2d 182 (1939) (“it is improper to permit the jury in arriving at its verdict to consider papers or documents not in evidence and which tend to influence the verdict of the jury”).
In State v. Williamson, 72 Haw. 97, 807 P.2d 593 (1991), this court reiterated its strong disfavor of a jury’s consideration of extraneous material. We said that upon discovery of outside influence during the deliberation process which
could substantially prejudice the defendant’s right to a fair trial, a rebuttable presumption of prejudice is raised. The trial judge is then duty bound to further investigate the totality of circumstances surrounding the outside influence to determine its impact on jury impartiality. The standard to be applied in overcoming such a presumption is that the outside influence on the jury must be proven harmless beyond a reasonable doubt.*478Emmanuel G. Guerrero, Deputy Public Defender, for defendant-appellant. James H. S. Choi, Deputy Prosecuting Attorney, for plaintiffappellee.
Williamson, 72 Haw. at 102, 807 P.2d at 596 (citations omitted). In the case at bar, neither appellant nor appellee can demonstrate whether there was a prejudicial effect because neither they nor the trial court sought to determine if the materials were actually used by the jury in deliberations. The record does not reveal for what intended purpose the materials were brought to the jury room. Absent a determination by the trial court that prejudice did not occur, we cannot conclude that the presumption of prejudice has been rebutted.
The egregious error of constitutional dimension commands us to vacate the conviction and remand for a new trial.