Matthew Perry, the troubled star of the smash hit TV sitcom "Friends," was found dead at his home in Los Angeles on Saturday, US media reported. He was 54.

First responders found Perry unconscious in a hot tub at his house and were unable to revive him, law enforcement sources told the Los Angeles Times.

"We responded at 4:10 pm… It is a death investigation for a male in his 50s," a Los Angeles Police Department spokesman told AFP, without confirming the deceased's name.

A fire department spokesman confirmed it had responded to a "water emergency," which could refer to a "pool, spa, bathtub or fountain," but could not confirm reports that Perry had drowned.

Perry was best known for his portrayal of the wise-cracking Chandler Bing on the wildly popular "Friends," which ran for 10 seasons from 1994 to 2004.

"Friends" followed the lives of six New Yorkers navigating adult life, dating, and careers. It was a mainstay of NBC's much-vaunted 1990s and early 2000s television lineup and drew a massive global following. 

During the height of his success, Perry battled for years with addiction to painkillers and alcohol and attended rehabilitation clinics on multiple occasions.

Perry experienced health problems including a burst colon in 2018 due to his drug usage, which required multiple surgeries and the use of a colostomy bag for months after.

In his memoir "Friends, Lovers and the Big Terrible Thing," published last year, Perry described going through detox dozens of times and spending millions of dollars in repeated attempts to get sober.

Perry dedicated the book to "all of the sufferers out there," and wrote in the prologue: "I should be dead."

He wrote: "People would be surprised to know that I have mostly been sober since 2001. Save for about sixty or seventy little mishaps over the years."

TMZ, which first reported the news Saturday, said that no drugs were found at the scene. The celebrity news outlet said Perry was found by his assistant, who called 911.

The LA Times and TMZ both said there were no signs of foul play, citing anonymous sources. 

Reactions poured in from the Hollywood community on social media as news of Perry's death spread.

"Oh no!!! Matthew Perry!! You sweet, troubled soul!!" wrote Mira Sorvino, who starred with Perry in the 1994 television movie "Parallel Lives."

"May you find peace and happiness in Heaven, making everyone laugh with your singular wit!!!"

Josh Charles, who appeared with Perry on "The Good Wife," wrote: "Awful news. RIP brother."

Warner Bros. TV, which produced "Friends," wrote: "We are devastated to learn of Matthew Perry's passing. He was a true gift to us all.

"Our heart goes out to his family, loved ones, and all of his fans."

Perry was born in Massachusetts in 1969 and was raised between Montreal and Los Angeles after his parents separated.

His mother was a Canadian journalist who served as press secretary to Prime Minister Pierre Trudeau. His father was a US actor. 

As a young teenager, Perry was a nationally ranked tennis star in Canada before moving permanently to California and pursuing acting.

In the 1980s, Perry had guest roles in popular shows such as "Charles in Charge" and "Growing Pains."

He was the final, and youngest, lead actor to be cast for "Friends."

Perry's character — the group's most sarcastic and quick-witted, but occasionally awkward and insecure, member — quickly became a fan favorite.

Perry and his co-stars — Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc and David Schwimmer — negotiated $1 million each, per episode, by the end of their colossally popular and zeitgeist-setting 236-episode run.

In a sign of the show's enduring appeal, the gang reportedly pocketed $2.5 million each for a reunion episode in 2021.

During that episode, Perry's slurred speech prompted concern among fans.

Perry also surprised his costars by admitting to having suffered severe anxiety "every night" during the filming the sitcom.

As well as "Friends," Perry appeared in movies such as "Fools Rush In" and "The Whole Nine Yards."

He was nominated for five Emmys, including two for guest appearances on "The West Wing," but never won the prestigious television award.

Perry never married.

His representatives did not immediately respond to AFP's request for comment.