People.com said the cause of his death has not been determined, but Renfro had a history of drug abuse.
Renfro spent Monday evening at a Los Angeles apartment with friends, was heard snoring during the night, but was found not breathing later Tuesday morning, the magazine said.
Craig Harvey, chief investigator for the Los Angeles county coroner, said Renfro's friends called 911, but paramedics declared Renfro dead at the scene at about 9 a.m.
Although he had been convicted of several drug offenses and struggled with addiction for years, TMZ.com cited sources who said he had been working hard to stay clean in recent months.
Celebrity Families of 2014 [PHOTOS]