Celebrity rehab star Jeff Conaway on the verge of death

May 19, 2011 at 11:14 a.m. ET

Actor Jeff Conaway is in a coma and on the verge of death after a drug overdose that friends are calling a suicide attempt.

Jeff ConawayGrease actor Jeff Conaway tried to kill himself by overdosing on drugs, and has nearly succeeded: His manager says he is in a deep coma and on the verge of death.

Conaway, who participated in Celebrity Rehab back in 2008, was found unconscious in his Encino, California home on May 11.

"A friend went to look for him because he wasn't responding to messages," said manager Phil Brock. "We hope and pray, but doctors aren't optimistic. These could be his final moments. He slightly moved his head three days ago but since, there's been no sign he'll recover."

Conaway has been under a great deal of strain as of late: He accused his ex-fiancée of injecting him with drugs and planting cocaine in his house to get him busted, while she accused him of punching her in the face while she was driving, according to RadarOnline.

The 60-year-old actor played Kenickie in the 1978 film version of Grease before a four-year stint on the hit sitcom Taxi. His years of battling drug addiction led him to join the cast of Celebrity Rehab with Dr. Drew, where viewers saw him undergo extremely dangerous physical withdrawal symptoms.

Image courtesy Rachel Worth / WENN