Chris Pizzello / Invision/AP 1 / 4
Chris Pizzello / Invision/AP 1 / 4

LOS ANGELES (AP) -- Jeff Conaway's manager says the former star of "Taxi" and "Grease" is in a coma following a drug overdose, possibly from pain pills.

Manager Phil Brock says the 60-year-old actor was found unconscious on May 11. He is hospitalized in critical condition.

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Brock says Conaway is in a coma in an Encino, Calif., hospital and his recovery is uncertain. The name of the hospital was not disclosed.

"He is in a coma and unresponsive at this time," his manager told E! News. "He turned his head two days ago, but nothing since."

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The actor is surrounded by friends and family, who have been anxiously awaiting an update from doctors, Brock said.

As part of the reality show "Celebrity Rehab" in 2008, Conaway discussed his addiction to drugs and alcohol.

His manager described Conaway 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."

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