Jeanne Manford, the founder of an international organisation for parents and relatives of LGBT family members has died at her home in California.

The 92-year-old founded PFLAG out of love for her gay son, she had been in declining health, said her daughter, Suzanne Swan on Tuesday.

Manford became an outspoken gay rights advocate in 1972 after her activist son, Monty, was beaten by police during a demonstration in New York City.

She penned a letter to the editor of the New York Post, declaring “I have a homosexual son and I love him.”

Manford went on to found a local support group for other parents the next year.

In those days, many of the group’s members were struggling to accept their children’s sexual orientations.

Parents, Families and Friends of Lesbians and Gays, (PFLAG), expanded across the US in 1980, and now has 350 chapters around the world.

“All of us – people who are lesbian, gay, bisexual, transgender, and straight allies alike – owe Jeanne our gratitude,” PFLAG officials said in an email statement.

“She paved the way for us to speak out for what is right, uniting the unique parent, family, and ally voice with the voice of LGBT people everywhere.”

Plans for a public memorial are pending.