CHICAGO (AFP) - A former auto worker who spent 45 years in prison for a murder he didn't commit has been awarded US$1.5 million (US$2.07 million) by the US state of Michigan as restitution for his wrongful conviction.

Richard Phillips was convicted in 1972 and sentenced to life in prison "based almost entirely" on the false testimony of one witness, according to prosecutors.

He was 27 when he entered prison and is now 73.

He was freed in 2018, after the University of Michigan's Innocence Clinic took up his case and declared him the longest imprisoned innocent man in America.

Phillips maintained his innocence throughout his incarceration.

"I would rather die in prison than to admit to something that I didn't do," he told WDIV television last year.

To support himself while waiting for officials to decide restitution, Phillips sold paintings he had made in prison.

The wait ended Friday when Michigan's top law enforcement official announced the US$1.5 million award - the largest of three restitution payments.

"Reentering society is profoundly difficult for wrongfully convicted individuals," Michigan Attorney General Dana Nessel said.

"We have an obligation to provide compassionate compensation to these men for the harm they suffered."

The state will also pay more than US$780,000 to Neal Redick, imprisoned nearly 16 years for sexual assault of a minor, before he was exonerated and released in 2007.

Also, former reserve police officer Raymond McCann will receive approximately US$40,000, after he was exonerated of perjury in 2017.