Burton originally pleaded not guilty to a single-count indictment charging conspiracy, 18 U.S.C. § 371 , and interstate transportation of an implement fitted for counterfeiting federal securities, 18 U.S.C. § 2314 . On November 4, 1968, he appeared with counsel, changed his plea to guilty, and was thereafter sentenced to prison for a term not to exceed two years.

The entire colloquy between Burton and the court concerning acceptance of the guilty plea is as follows:

On August 28, 1969, appellant moved the District Court, pursuant to 28 U.S.C. § 2255 , to vacate the conviction and to allow him to plead anew contending, inter alia that his plea was not voluntarily entered. It is from the denial of that motion that Burton appeals.

Rule 11, Fed.R.Crim.P., provides:

From the foregoing record, there is no indication that the trial court undertook sufficiently to satisfy itself that there was a factual basis for the guilty plea. 4 The short statement by the accused that “Well, only that I ask the Court to show me leniency, because the matter of this conspiracy consisted of actually five of us. It is my understanding that two others have pled guilty also . . .,” was not a sufficient foundation upon which to find a factual basis for the plea. At most, that statement merely reflects Burton’s unlearned explanation and is the very kind of unskilled conclusion that the trial court must carefully examine.

The prosecution emphasizes that Burton twice assured the trial judge that he was satisfied with the advice and assistance of his appointed counsel. We have long held, however, that assistance of counsel is but one factor to be considered and is far from conclusive. 5 Moreover, mere presence of counsel in the case at hand is particularly inconclusive, for the record rather clearly suggests that defense counsel himself was not even certain of either the charge or the possible penalty. 6

*1186 The prosecution also contends that Burton admitted to the presentence probation officer that he had sent a check cashing machine to one of his co-defendants, and that this contention, if true, provides a factual basis for the plea. This argument also fails. First, since the alleged admission occurred subsequent to the acceptance of the guilty plea, no reliance upon it could have been placed by the court in making the prior Rule 11 determination. In Heiden v. United States, 353 F.2d 53 (9th Cir. 1965), we emphasized:

Id. at 55.

Secondly, Burton stresses that he accompanied the alleged statement with repeated protestations of innocence based upon the absence of either his knowledge of any illegal use to be made of the machine, or of his intent to participate in the crime. This denial of guilt, even if combined with an admission of some involvement, should, we think, have prompted the court to pursue further inquiry. 7

Having concluded that there was a failure to heed the strict requirements of Rule 11, we now consider the appropriate remedy. We are urged both to vacate the District Court’s Order denying the section 2255 motion and to set aside Burton’s convictions for violation of 18 U.S.C. §§ 371 , 2314, thus affording him a new opportunity to plead.

In Castro v. United States, 396 F.2d 345, 348 (9th Cir. 1968), which reaffirmed Heiden v. United States, supra, our court declared:

The aim of the Heiden court was apparently to encourage trial courts to follow the mandate of Rule 11, and, in the absence of such compliance, to protect defendants from any resulting prejudice.

Heiden, 353 F.2d at 55 . The proper construction of our rule was adopted in McCarthy v. United States, 394 U.S. 459 , 89 S.Ct. 1166 , 22 L.Ed.2d 418 (1968):

394 U.S. at 469 , 89 S.Ct. at 1172 .

Thus, under established principles, Burton was undeniably prejudiced by the court’s failure wholly and fully to comply with the specific mandates of Rule 11. Were we to simply remand this cause with instructions to conduct a hearing to determine whether appellant knowingly and voluntarily entered his plea, and whether there was, at the time of pleading, a sufficient factual basis upon which to accept the plea of guilt, Burton would be put to the very burden which, under Heiden , those in his position were sought to be spared.

Finally, we conceive it to be our duty, exercising our supervisory power, to assure that there be the strictest compliance with the requirements of Rule 11. 8 That this court has such supervisory power is hardly deniable. In La Buy v. Howes Leather Co., 352 U.S. 249 , 77 S.Ct. 309 , 1 L.Ed.2d 290 (1957), the United States Supreme Court held that “ . . . supervisory control of the District Courts by the Courts of Appeals is necessary to proper judicial administration in the federal system.” Id. at 259-260 , 77 S.Ct. at 315 . 9 Moreover, this pronouncement by the Nation’s supreme judicial authority has been reaffirmed by every Court of Appeals, including our own, that has confronted the issue. In a very recent opinion of this court, Guam v. Camacho, 470 F.2d 919 (9th Cir. 1972), Chief Judge Chambers' acknowledged the existence of the “supervisory power” of this court. See also United States v. Thomas, 146 U.S.App. D.C. 101, 449 F.2d 1177 (1971) (en banc); United States v. Daniels, 446 F. 2d 967 (6th Cir. 1971); In re Ellsberg, 446 F.2d 954 (1st Cir. 1971); United States v. Jones, 140 U.S.App.D.C. 70 , 433 F.2d 1176 (1970), cert. denied, 402 U.S. 950 , 91 S.Ct. 1613 , 29 L.Ed.2d 120 (1971) ; Dellinger v. Mitchell, 143 U.S. App.D.C. 60, 442 F.2d 782 (1971); Ralph v. Warden, 438 F.2d 786 (4th Cir. 1970), cert. denied, 408 U.S. 942 , 92 S. *1188 Ct. 2869 , 33 L.Ed.2d 766 (1972); United States v. Butera, 420 F.2d 564 (1st Cir. 1970); United States v. Fioravanti, 412 F.2d 407 (3d Cir.), cert. denied, 396 U. S. 837 , 90 S.Ct. 97 , 24 L.Ed.2d 88 (1969) ; United States v. Brown, 411 F.2d 930 (7th Cir. 1969), cert. denied, 396 U.S. 1017 , 90 S.Ct. 578 , 24 L.Ed.2d 508 (1970) ; Boeing Co. v. Shipman, 411 F.2d 365 (5th Cir. 1969) (en banc); United States v. Dooling, 406 F.2d 192 (2d Cir. 1969), cert. denied, 395 U.S. 911 , 89 S.Ct. 1744 , 23 L.Ed.2d 224 (1969); Sanders v. Russell, 401 F.2d 241 (5th Cir. 1968); Pea v. United States, 130 U.S.App.D.C. 66 , 397 F.2d 627, 637 (1968) (rehearing en banc); ACF Industries, Inc. v. Guinn, 384 F.2d 15 (5th Cir. 1967), cert. denied, 390 U.S. 949 , 88 S.Ct. 1039 , 19 L.Ed.2d 1140 (1968); Government of Virgin Islands v. Lovell, 378 F.2d 799 (3d Cir. 1967); Thomas v. United States, 368 F.2d 941 (5th Cir. 1966); Tate v. United States, 123 U.S. App.D.C. 261, 359 F.2d 245 (1966); United States v. Freeman, 357 F.2d 606 (2d Cir. 1966); Black v. United States, 122 U.S.App.D.C. 393 , 355 F.2d 104 (1965); United States v. Inman, 352 F.2d 954 (4th Cir. 1965); Ford v. United States, 122 U.S.App.D.C. 259 , 352 F.2d 927 (1965) (en banc); Smith v. Katzenbach, 122 U.S.App.D.C. 113 , 351 F.2d 810 ; Natural Resources, Inc. v. Wineberg, 349 F.2d 685 (9th Cir. 1965), cert. denied, 382 U.S. 1010 , 86 S.Ct. 617 , 5 L.Ed.2d 525 (1966); Jones v. United States, 119 U.S.App.D.C. 284 , 342 F.2d 863 (1964) (en banc); United States v. D’Angiolillo, 340 F.2d 453 (2d Cir.), cert. denied, 380 U.S. 955 , 85 S.Ct. 1090 , 13 L.Ed.2d 972 (1965); United States ex rel. Sturdivant v. New Jersey, 289 F.2d 846 (3d Cir.), cert. denied, 368 U.S. 864 , 82 S.Ct. 109 , 7 L.Ed.2d 61 (1961); Wildeblood v. United States, 106 U.S.App.D.C. 338 , 273 F.2d 73 (1959) (Burger, J.); Delaney v. United States, 199 F.2d 107 (1st Cir. 1952); Helwig v. United States, 162 F.2d 837 (6th Cir. 1947).

Accordingly, the District Court’s Order is reversed. Upon remand, the judgments of conviction will be vacated and Burton will be allowed a new opportunity to plead to the charges of the indictment.

Reversed and remanded.

. There were two charges, alleged in the same count, not a simple “this” charge.

. See footnote 1, supra.

. Only § 371 pertained to conspiracy.

. Burton’s statement, in response to one of the Court’s inquiries, to the effect that he was pleading guilty “because [he was] guilty,” goes to the question of the volun-tariness of his plea but is not significantly relevant, in the whole context, to the question of whether this Court, upon the record and in the concluding words of Rule 11, “satisfied [itself] that there [was] a factual basis for the plea.” (Emphasis supplied.)

. Gomez v. United States, 396 F.2d 323 (9th Cir. 1968) ; Munich v. United States, 337 F.2d 356 (9th Cir. 1964).

. “MR. DE LEON [Burton’s attorney] : Excuse me. The charge is on conspiracy, is it not?

MR. MALINSKY: There is a one-count charge which alleges a violation of

Title 18, 371 and 2314, both in the same count.

MR. DE LEON: I just have a question. Is the maximum governed by Section 371 — five years?

MR. MALINSKY: Your Honor, there is a violation of two provisions of the Code alleged in the single count, and there is a different penalty for each violation.

I think that the maximum possible sentence that could be imposed is imprisonment up to ten years, because that is the penalty for violation of Title 18, Section 2314.

THE COURT: That’s probably true, but as long as you join them both, I would take the low one.

MR. DE LEON: Your Honor, the defendant wishes to change his plea to guilty, from not guilty to guilty.” (Emphasis supplied).

. Our recent decision in United States v. Sherman, 474 F.2d 303 (9th Cir. 1973), is clearly distinguishable. In contrast to our case, the appellant there “ . discussed the details of the crime at some length” with the trial judge thus providing the court with the required factual basis for acceptance of the plea. Id. at 307 .

. Our dissenting Brother characterizes our comments concerning the supervisory power of this court as “dictum.” The majority does not intend that it be so interpreted. The overwhelming body of authority which the majority has cited establishes, beyond doubt, that supervisory power is vested in the courts of appeal, and it is most assuredly appropriate for that power to be exercised in a case such as this. We recognize, of course, that the McCarthy holding is not retroactive, but long before the opinion in McCarthy was issued, this court’s opinion in Heiden had become, and, as expressly approved by the Supreme Court in McCarthy , remains viable. Thus, the majority, mindful of Heiden’s controlling principle, has relied upon the existence of this court’s supervisory power in reaching its dispositive conclusion.

. See also Lego v. Twomey, 404 U.S. 477 , 479 n.1, 92 S.Ct. 619 , 30 L.Ed.2d 618 (1972).