Debra Chasnoff, the filmmaker who made history as the first woman to thank her lesbian partner when accepting an Oscar, has died aged 60.

The Philadelphia-born documentary filmmaker and activist died of breast cancer, according to website Mombian.

Chasnoff's films addressed progressive social issues, with her production company GroundSpark producing and distributing films, educational resources and campaigns on issues including environmental concerns, affordable housing and how to prevent prejudice.

She won the Academy Award for Best Documentary Short Subject for her 1991 film Deadly Deception: General Electric, Nuclear Weapons, and our Environment – which exposed the health and environmental effects of nuclear materials produced by General Electric.

Her work led to GE leaving the nuclear weapons industry. Upon receiving her Academy Award at the 1992 Oscar ceremony, she thanked her then-partner Kim Klausner.

In her speech, she said: ''I am very grateful to my friends and family, particularly to Kim Klausner, my life partner, who always had faith in me, and to our son Noah who reminds me on a daily basis of why it's so important not to give up and to keep working for peace and justice.''

Discussing her speech in an interview with Lesbian News Magazine in 2009, she said: "When I did it, I thought, this is really astonishing to me that this hasn't happened before.

''We all know plenty of gay people who have won Academy Awards but we're all just quiet about it. I couldn't imagine having that profound of an honor and not acknowledging my partner."

The speech was the first time Chasnoff 'came out' to the public. She went on to marry another woman, artist Nancy Otto.

She made several acclaimed documentaries dealing with LGBT issues, collaborating with then partner Klauser on the 1985 film Choosing Children.

Chasnoff is survived by wife Nancy and her two children Noah and Oscar Chasnoff.