NEW YORK: Cameron Douglas, son of Oscar winner Michael Douglas, was sentenced Wednesday to 54 additional months behind bars for drug possession while in prison, where he had already been serving time on drugs charges.

The 33-year-old from of one of Hollywood's most famous acting families, was sentenced in April last year to five years for drug trafficking, but has been caught possessing drugs while in jail.

In handing down the sentence, Judge Richard Berman rejected a Douglas plea for clemency, sending shockwaves through the court where several members of the celebrity-studded family were seated.

“I plead with you, Judge Berman, to grant me the opportunity to treat this malignant affliction,” said Douglas, who is also the grandson of film icon Kirk Douglas.

Four Douglas relatives, but not his parents, were in the court, some sobbing or looking stunned.

Once an aspiring actor, Cameron Douglas was arrested in July 2009 in a New York hotel with large quantities of methamphetamines.

The prosecution said he was trafficking methamphetamines, also known as crystal meth, in addition to using the drugs himself. He either sent or transported packets of the drugs to New York from California and had cash payments sent by courier to a California hotel.

He was previously jailed in 1999 and 2007 on drug charges.