Bill Cosby’s wife has likened her husband’s sexual abuse conviction and the claims of dozens of women against him to “mob justice” in an angry outburst.

Camille Cosby commented on the case for the first time on Thursday in a statement issued through a spokesman a week after her husband of 54 years was convicted of aggravated indecent assault.

She angrily called her husband’s chief accuser, Andrea Constand, a liar and called for a criminal investigation into the prosecutor behind her husband’s sexual assault conviction, saying the case was “not real justice” and a “tragedy” that must be undone.

She compared Cosby’s treatment to that of Emmett Till, a 14-year-old black boy lynched in 1955 over false allegations he flirted with a white woman.

“Once again, an innocent person has been found guilty based on an unthinking, unquestioning, unconstitutional frenzy propagated by the media and allowed to play out in a supposed court of law,” she said.

“This is mob justice, not real justice. This tragedy must be undone not just for Bill Cosby, but for the country.”

Ms Constand’s lawyer issued an angry statement in response to Mrs Cosby’s claims.

“Twelve honorable jurors — peers of Cosby — have spoken,” lawyer Dolores Troiani said.

“There is nothing else that needs to be said.”

The 80-year-old Cosby is on house arrest while awaiting sentencing that could put him in prison for the rest of his life.

Mrs Cosby compared the dozens of other women who’ve accused her husband to a “lynch mob” spurred on by the media’s “frenzied, relentless demonisation” of the man who earned a reputation as America’s Dad playing Dr Cliff Huxtable on the top-rated family sitcom The Cosby Show.

She compared his treatment to Mr Till, the black teenager who was kidnapped and murdered after witnesses said he whistled at a white woman in a Mississippi grocery store in 1955, and Darryl Hunt, a black man wrongly convicted of raping and killing a white woman in North Carolina in 1984. Constand is white.

“Someday the truth will prevail, it always does,” Mrs Cosby said.

She said her husband’s prosecution was politically motivated, repeating his team’s contention that he had been a pawn in a heated race for district attorney.

-with AAP