Philip Seymour Hoffman
Oscar winner Philip Seymour Hoffman allegedly admitted checking himself into rehab after snorting heroin.

Oscar winning actor Philip Seymour Hoffman lost his life on Feb. 2 to an apparent overdose of drugs, a vice he has been struggling with for a good part of his life.

Although he had checked into a rehab last year, Hoffman was unable to keep his addiction under control, and was found dead in his New York City apartment with a hypodermic needle still in his arm. A packet suspected to be heroin was found next to his lifeless body, multiple reports said.

In the months leading up to his death, Hoffman was said to be troubled and this might have increased his dependency on drugs. Hoffman split from his girlfriend of 14 years, Mimi O'Donnell, just months before his death, and had been staying $10,000-a-month apartment, according to Mail Online

O'Donnell is said to be devastated at the loss. "Mimi is inconsolable," a source told Showbiz Spy. "He had his problems, but she thought he was on the road to recovery following his recent rehab stint."

"Mimi already had a tough few days, after the recent hoax that claimed Philip had died."

Hoffman's last public appearance was during the Sundance Festival, where he appeared worn out and troubled. Reportedly, he kept away from the media, and denied various requests for interviews.

A neighbour of Hoffman's also echoed that the actor seemed unwell. "He did not look well recently — like he was out of it," the woman said, according to New York Post. "I think him and his woman friend were off and on. He lived down here for a long time and was well liked, but everyone knew he had substance-abuse problems," she added.

Hollywood is in shock over Hoffman's death, and stars have been taking to their social networking sites to express their sadness.

Check out some of the tweets below.

Phillip Seymour Hoffman was a genius, brave and sweet. Can't believe he's gone. Huge loss. My deepest sympathy for his wife and children - Susan Sarandon

Oh boy what is HAPPENING? All these beautiful people leaving too early. What a sweet soul, Phil Hoffman was, what a sad, sad day – Minnie Driver

Shocked to hear of Philip Seymour Hoffman's death. If you missed him as Willy Loman, you missed a Willy Loman for all time – Steve Martin

Just hearing about Phillip Seymour Hoffman. Devastating. What an amazingly gifted actor. RIP – Justin Timberlake