US comedian Garry Shandling has died at the age of 66, the Los Angeles Police Department has confirmed.
The actor died on Thursday at a hospital in Los Angeles but the cause of death has not yet been disclosed.
The Los Angeles Fire Department responded to a medical emergency on Thursday morning and Shandling was transported to St. John's Hospital by ambulance. He was later pronounced dead.
Sources have told US entertainment site TMZ that Chicago-born Shandling died from "a massive heart attack".
The award-winning comic created It's Garry Shandling's Show in 1986 and pioneered a form of docudrama comedy which influenced Britain's Ricky Gervais, among others.
Noted for its use of breaking the fourth wall, it featured Shandling essentially playing himself and often speaking directly to the camera.
Shandling followed the Emmy award-nominated series with The Larry Sanders Show in 1992.
Considered by leading critics and industry figures as his comic masterpiece, it starred Shandling as an egotistical late-night TV host.
An innovative HBO series, The Larry Sanders Show also featured celebrities playing parodies of themselves.
Among the many honours the Emmy Award-winning series took home was a Bafta for 1999 outstanding international programme and two British Comedy Awards.
Recently seen in Jerry Seinfeld's web-series Comedians In Cars Getting Coffee, Shandling is featured in The Jungle Book movie, which is set to be released in April.
On his official Twitter account, The Office creator Gervais tweeted: "RIP the great Garry Shandling. Surely, one of the most influential comedians of a generation."