updated 10/21/2011 AT 11:00 AM ET
•originally published 10/21/2011 AT 11:30 AM ET
Cameron Douglas, who is serving a five- year federal prison sentence for drug dealing, pleaded guilty Thursday to possessing drugs in his jail cell.
For the latest charges, the son of actor Michael Douglas faces a maximum sentence of 20 years in prison, followed by three years of supervised release, plus a $250,000 fine.
Douglas, 32, is charged with possessing items that tested positive for cocaine and heroin, which were found in his cell by an investigator. Assistant U.S. Attorney Justin Anderson told the court one of the substances tested positive for methadone, which he described as “something that people take when they’re coming off a heroin addiction in order to facilitate the withdrawal,” according to a court transcript.