NEW YORK/ WASHINGTON DC, UNITED STATES (REUTERS) - Edith Windsor, whose lawsuit prompted the Supreme Court decision to grant gay couples federal benefits, has died.

Her second wife, Judith Kasen-Windsor, confirmed the death Tuesday, saying in a statement that "the world lost a tiny but tough as nails fighter for freedom, justice and equality."

Windsor sued the federal government after being forced to pay additional estate taxes because it did not recognise her marriage to Thea Spyer under the Defense of Marriage Act (Doma).

Spyer had died in 2009 and Windsor was unable to claim certain tax benefits under the law.

The Supreme Court then ruled in favour of Windsor.

Edith Windsor, plaintiff Windsor versus the United States, said: "Children born today will grow up in a world without Doma. And those same children who happen to be gay will be free to love and get married as Thea and I did, but with the same federal benefits, protections and dignity as anyone else. If I had to survive Thea, what a glorious way to do it. And she would be so pleased."

Her 2013 victory would be credited with laying the groundwork for the landmark 2015 Supreme Court ruling in another case that legalized same-sex marriage nationwide.

No cause of death was given. Windsor was 88 years old.