Oscar winner Philip Seymour Hoffman smiles during a photo call for the World Premiere of the film "Mission Impossible III" in Rome in this April 24, 2006 file photo. Hoffman, one of the leading actors of his generation, who won an Academy Award for his title role in the film "Capote," was found dead in his Manhattan apartment on February 2, 2014.  [Photo/Agencies]

NEW YORK - Oscar-winning US actor Philip Seymour Hoffman was found dead Sunday at his New York City apartment in Manhattan, a New York Police Department source said.

Media reports that the 46-year-old actor, who won an Oscar for the film "Capote," was died of an apparent drug overdose. However, the cause of his death is still not officially disclosed.

Police responded to the scene in Manhattan's West Village after receiving a 911 emergency call, the source said. The source gave no further details.

The Wall Street Journal, which broke the story, said Hoffman was found unconscious with a hypodermic needle in his arm late Sunday morning by a screenwriter in the bathroom of his apartment.

He was pronounced dead at the scene, the report said.

Born in upstate New York, Hoffman won an Academy Award for the 2005 biographical film "Capote," in which he played writer Truman Capote. He also received three Academy Award nominations as best supporting actor -- "The Master" in 2013, "Doubt" in 2009 and " Charlie Wilson's War" in 2008.

Hoffman leaves behind a longtime partner, Mimi O'Donnell, and three children.

His family said they were devastated by his death.

"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," his family said in a statement.

New York City Mayor Bill de Blasio tweeted a statement as well.

"Saddened by Philip Seymour Hoffman's tragic and untimely passing. Today New York mourns the loss of one of stage and screen 's greats," reads the mayor's tweet.