Report: Clooney to make appearance on 'ER'

LOS ANGELES, Jan. 22 (UPI) -- Hollywood actor George Clooney is to make an appearance on "ER" as his former television drama wraps up its 15th and final season, sources say.

Show insiders told People magazine that "ER" co-creator John Wells has ordered a closed set while Clooney tapes his scenes in an effort to keep his work there private. How many episodes the "Ocean's 11" and "Syriana" star might appear in and when they may run were unclear.

NBC, Warner Bros. and Clooney's publicist all declined to comment on the story, People.com said.

Clooney played Dr. Doug Ross on the TV medical drama from 1994 to 1999. He returned for a cameo in an episode in 2000.