Actor Morgan Freeman has led tributes at the annual Academy Awards ceremony to fellow Hollywood star Gene Hackman, whose death last month is under police investigation.

"This week, our community lost a giant and I lost a dear friend," said Freeman, who worked with Hackman in two films, including 1992's Unforgiven, which won Hackman his second Oscar.

"Like everyone who ever shared a scene with him, I learned he was a generous performer whose gifts elevated everyone's work," Freeman said.

Hackman, 95, and his wife Betsy Arakawa, 65, were found dead at their home in New Mexico days ago.

"He received two Oscars but more importantly he won the hearts of film-lovers all over the world," Freeman said in his speech during Sunday night's 97th Academy Awards ceremony in Los Angeles.

He added that Hackman had told him: "I don't think about legacy, I just hope people remember me as someone who tried to do good work."

"Gene, you'll be remembered for that and so much more. Rest in peace, my friend."

Morgan, 87, also starred alongside Hackman in 2000 film Under Suspicion.

The Oscars ceremony also featured an in memoriam segment, where clips from some of the character actor's best films over his 60-year career were shown.

Hackman was known for such movies as The French Connection, The Conversation, Bonnie and Clyde, Mississippi Burning and Superman, but had not starred in a film since his retirement from acting in 2004.

Officials found Hackman and Ms Arakawa's bodies on Wednesday, about 10 days after investigators believe he died.

The results of a post-mortem examination are pending, and officials say it may take weeks to determine how the couple died.

The Oscars ceremony also featured a tribute to music producer Quincy Jones, led by Whoopi Goldberg, Oprah and Queen Latifah, who sang a song in his memory.

Jones received seven Oscar nominations in in his lifetime, including in 1967 when he became the first black composer to be nominated for the original song category.

Jones died in November at the age of 91.