Prosecutors have asked the US Supreme Court to review comedian Bill Cosby's overturned conviction for drugging and sexually assaulting a woman 15 years ago, they announced Monday.

"The US Supreme Court can right what we believe is a grievous wrong," Kevin Steele, district attorney for Montgomery County, Pennsylvania said in a statement announcing that the appeal had been filed last Wednesday.

Cosby was freed from prison on June 30 following a ruling by the Pennsylvania Supreme Court that he had been denied a fair trial, in a move seen as a blow to the #MeToo movement.

At the time of his release, the comedian had been jailed since 2018 for assaulting Andrea Constand at his Philadelphia mansion in 2004 when she was an employee at Temple University.

In its decision, the Pennsylvania Supreme Court focused on a non-prosecution agreement between a former district attorney and Cosby over evidence he gave in a civil case.

Cosby had admitted giving Quaaludes, a now banned party drug, to women with a view to having sex with them in deposition testimony in that case.

However the testimony was then used against him in a criminal trial years later brought forward by Steele.

Cosby's lawyers argued he believed that testimony was immune from prosecution in criminal court when he gave it.

US actor Bill Cosby arrives at court in September 2018 in Norristown, Pennsylvania for his sentencing
US actor Bill Cosby arrives at court in September 2018 in Norristown, Pennsylvania for his sentencing AFP / Brendan Smialowski

They argued that the non-prosecution agreement meant he should not have been charged, which the Pennsylvania Supreme Court justices agreed with.

However Steele said Monday that "petitioning to ask the High Court for review was the right thing to do," and denounced the "far-reaching negative consequences" of the Pennsylvania Supreme Court's decision.

In his appeal to the Pennsylvania Supreme Court, Cosby presented a 2005 press release as evidence of the first prosecutor's statement not to prosecute him.

Steele said Monday that the decision merited appeal because it set a precedent "that prosecutors' statements in press releases now seemingly create immunity."

A spokesman for the 84-year-old actor criticized the latest appeal as "a pathetic last-ditch effort," in a statement quoted by multiple US news outlets.

Cosby served more than two years of a three-to-ten-year sentence for aggravated indecent assault and has always maintained his innocence.

Although more than 60 women charged that they had been victims of sexual assault by Cosby, he was tried criminally only for Constand's assault, since the statute of limitations had expired in the other cases.

Cosby shattered racial barriers with his Emmy-winning role on "I Spy" in the 1960s and also starred as a dad and doctor on the hit TV series "The Cosby Show" in the 1980s.