Jeff Conaway, the star of Taxi and Grease, is in a coma following a drug overdose.
His manager Phil Brock said the 60-year-old was found unconscious on May 11. He is in hospital in a critical condition. Mr Brock said Jeff is in a coma in a California hospital and his recovery is uncertain.
As part of the reality show Celebrity Rehab in 2008, Jeff discussed his addiction to drugs and alcohol.
His manager described Jeff as a "gentle soul" but one who has been unable to "exorcise his demons".
Conaway appeared in the 1978 movie musical Grease and starred in the TV series Babylon 5.