Cameron, 37, was sentenced to a five year prison term for possessing heroin and selling other drugs in 2010, a sentence extended after he confessed to smuggling illegal substances into jail.

He had been scheduled to leave prison in 2018, but according editors at the New York Post gossip column Page Six, has been released to a halfway house.

The disgraced actor, who appeared with his father, 71, and movie icon grandfather Kirk Douglas, 99, in the 2003 comedy It Runs in the Family, spent two years in solitary confinement at Maryland's Cumberland Federal Corrections Institute from 2012 to 2014.

Now Cameron, Michael's only son by his first wife Diandra Luker, is now reportedly set to write a book about his fall from grace and his experiences behind bars.

"Cameron will talk about his struggle being the son and grandson of Hollywood icons, and then his bad decisions which led him to jail, and then solitary confinement," a source tells Page Six. "He is staying low-key after his release and plans to spend time with his father and mother. He believes this is a new start, and a chance at a new life."

Despite his son's troubles, Michael has regularly visited him in jail and used his acceptance speech when honoured for his role in Liberace bio-pic Behind the Candelabra at the 2013 Emmy Awards to question the severity of the U.S. prison system.

"I'm questioning the system," Michael said in his speech. "At first I was certainly disappointed with my son, but I've reached a point now where I'm disappointed with the system. If you happen to have a slip, they punish you. In my son's case, he has spent almost two years in solitary confinement."