Actor Philip Seymour Hoffman has been found dead in his Manhattan apartment after an apparent drug overdose.
The Hollywood star, who won an Academy Award for Best Actor for his performance in the 2005 film Capote, was 46 years old.
The father-of-three was found dead in his bathroom with a syringe in his arm, according to law enforcement sources.
Speaking on condition of anonymity, two officials said small envelopes they suspect contained heroin were found in the Greenwich Village apartment. They said the bags were marked with the ace of hearts and spades.
His family said in a statement: "We are devastated by the loss of our beloved Phil and appreciate the outpouring of love and support we have received from everyone.
"This is a tragic and sudden loss and we ask that you respect our privacy during this time of grieving. Please keep Phil in your thoughts and prayers."
The actor's body was removed from the apartment building in the West Village on Sunday night.
Sky's US correspondent Greg Milam said: "The shock across the United States is being felt very keenly."
A string of Hollywood stars have paid tribute, including Kevin Bacon, Jim Carrey and British actor Gary Oldman, who said Hoffman was "very special".
Hoffman's other film credits included The Big Lebowski, The Hunger Games: Catching Fire, Mission: Impossible III, and The Talented Mr Ripley.
Last year, he revealed he was forced to check himself into rehab after taking prescription pills and snorting heroin, having managed to stay clean for 23 years.
He reportedly admitted he "started off taking prescription pills which escalated to snorting heroin".
The star was apparently concerned he was about to lose control and checked himself into a detox facility on the East Coast.
On leaving the centre after 10 days, Hoffman credited "a great group of friends and family" for the support and encouragement to get help.
"I went to rehab, I got sober when I was 22-years-old," he said in a 2006 interview.
"You get panicked ... and I got panicked for my life."
News of Hoffman's death came after his representatives denied a death hoax about the actor spread earlier in the week.
Born in 1967, in Fairport, New York, Hoffman became involved in acting at high school.
He went on to study at New York University's Tisch School of the Arts, where he graduated with a degree in Drama in 1989.
He got his first acting role in a 1991 episode of the long-running police drama Law and Order, but his big break came in the 1997 film Boogie Nights, starring alongside Mark Wahlberg.
In addition to his screen work, Hoffman was also a talented stage actor, gaining plaudits for his roles on Broadway.
He had recently been working on the last instalment of The Hunger Games franchise, in which he played the role of head gamemaker Plutarch Heavensbee.
He leaves his long-term partner and costume designer Mimi O'Donnell and their two daughters and son.
:: Watch Sky News live on television on Sky channel 501, Virgin Media channel 602, Freeview channel 82 and Freesat channel 202.