Surveillance footage capturing the outside of Jeffrey Epstein’s cell during his first suicide attempt in July is gone forever, prosecutors confirmed Thursday in a bombshell court filing.

The revelation comes after Assistant US Attorney Jason Swergold told White Plains federal Judge Kenneth Karas in December that the footage was missing — and then backtracked the next day, claiming it had been preserved.

In a Thursday filing, Swergold admitted that the Metropolitan Correctional Center had preserved footage amid the investigation — only it was the wrong cell in the Lower Manhattan jail.

“The Government has learned that the MCC inadvertently preserved video from the wrong tier within the MCC, and, as a result, video from outside the defendant’s cell on July 22 – 23, 2019 (i.e. the requested video) no longer exists,” the letter reads.

A lawyer for Epstein’s one-time cellmate, Nicholas Tartaglione, has been seeking the footage in order to prove that his client — a former cop who is awaiting trial for a quadruple homicide — is not responsible for the neck injuries Epstein sustained while they shared a cell weeks before the suicide.

The letter claims MCC staff were misled by a computer system that wrongly listed Tartaglione as being housed in a different cell during those dates — and therefore kept the footage from outside that incorrect cell.

Prosecutors say they realized the mistake after the facility turned over footage on Jan. 3.

“After reviewing the video, it appeared to the Government that the footage contained on the preserved video was for the correct date and time, but captured a different tier than the one where Cell-1 was,” reads the letter, referring to the cell shared by Tartaglione and Epstein.

To make matters worse, the MCC’s backup system hasn’t been working properly, meaning the video is gone for good.

“The Federal Bureau of Investigation … reviewed that backup system as part of an unrelated investigation and determined that the requested video no longer exists on the backup system and has not since at least August 2019 as a result of technical errors,” prosecutors wrote.

Tartaglione and his attorney Bruce Barket have repeatedly denied that the former Briarcliff Manor cop hurt Epstein, with Barket saying his client was cleared by investigators.

Epstein was found dead in August in the Lower Manhattan, where he was awaiting trial for sex trafficking.

His death was officially ruled a suicide by hanging, though a forensic pathologist hired by his brother says he believes Epstein was murdered.

Two corrections officers, Tova Noel and Michael Thomas, have been charged with falsifying documents claiming they checked on him the night of his death.

“It is mind-boggling to me that they would have preserved the wrong video, and erased the real video,” Barket said. “It is simply beyond the pale.”