Corruption squad probe missing escape film

Western Australia's corruption watchdog has ruled out misconduct, after it was discovered CCTV footage of a prison van escape was missing.

An internal report into the January 3 escape of Cameron John Graham and fellow inmate Kelden Fraser found that a dodgy lock allowed the pair to escape, and CCTV designed to film them in the van was not available.

WA's Corruption and Crime Commission (CCC) confirmed on Thursday they had been asked to investigate why the CCTV was missing from the prison van, amid "allegations of misconduct".

But after investigating whether anyone had tampered with, or ordered the destruction, of the footage, the CCC said they had found nothing untoward.

"The commission found that there is no suspected misconduct on the part of any public officer relating to the absence of the CCTV footage of the incident," a statement said.

However, the CCC did say a forensic analysis of the video recording equipment had identified "potential procedural and technical design issues associated with the CCTV system".

They said they had been referred to WA's Department of Corrective Services.

Contractor Serco has already been ordered to pay more than $700,000 in penalties and upgrades to the WA prison van fleet, after the escape of rapist Graham and fellow inmate Fraser.