Celebrity tributes are pouring in for Oscar-winning actor Gene Hackman, who is credited with helping define the “New Hollywood” cinema of the 1970s and went on to build a film career that spanned six decades.

The 95-year-old screen icon and his wife, Betsy Arakawa, 65, were found dead in their Santa Fe, New Mexico, home Wednesday, along with their dog. An investigation into their deaths is underway.

Rising to prominence in the late ’60s and early ’70s, Hackman established himself as one of the most distinctive and dependable film stars of his generation. His roles in classics such as “The French Connection,” “The Conversation” and “Unforgiven” made him one of the most respected performers in Hollywood.

In a tribute to the star, Dustin Hoffman said he met Hackman in acting school at the Pasadena Playhouse in their youth, and they would play conga drums like Marlon Brando, their hero. The longtime friends worked together on the 2003 film “Runaway Jury.”

“And Gene was like Brando, in that he brought something unprecedented to our craft, something people didn’t immediately understand as genius: He was expelled from our school after three months for ‘not having talent,'” Hoffman said. “It was the first time they ever did that. He was that good. Powerful, subtle, brilliant. A giant among actors. I miss him already.”

Marcia Gay Harden, who starred with Hackman in “Welcome to Mooseport,” said she was mesmerized by his work “even during rehearsals.”

“He was the real deal,” Harden said. “Every line was as if he was saying it for the first time.”

Clint Eastwood, who directed and starred in “Unforgiven” with Hackman — who won a best supporting actor Oscar for his role as a sadistic sheriff in the 1992 Western — said, “There was no finer actor than Gene.”

“Intense and instinctive. Never a false note. He was also a dear friend whom I will miss very much,” Eastwood said.

Hackman’s “Bat*21” and “The Royal Tenenbaums” co-star, Danny Glover, praised Hackman’s passion for acting, calling it “extraordinary.” “I appreciated his dedication and learned a great deal from him,” Glover said about the late actor.

Filmmaker Francis Ford Coppola, who directed Hackman in the 1974 neo-noir mystery “The Conversation,” called his death “The loss of a great artist.” In one of his most celebrated roles, Hackman played a surveillance expert who becomes tangled in a sinister situation after a client hires him to spy on a couple.

“Gene Hackman a great actor, inspiring and magnificent in his work and complexity,” Coppola wrote on Instagram. “I mourn his loss, and celebrate his existence and contribution.”