A mother has had her gay son's matrimonial ad published in an Indian newspaper after three leading dailies refused - the first such advert published in a country where homosexuality is illegal.

Padma Iyer placed the advert for her rights activist son Harish in the matrimonial pages of Mid-Day newspaper, the largest selling tabloid in India's financial and entertainment capital Mumbai.

"Seeking 25-40, Well-placed, Animal-Loving, Vegetarian GROOM for my SON (36, 5'11") who works with an NGO, Caste No Bar (Though IYER Preferred)," read the advertisement published on Tuesday.

We believe that human rights should be applicable to all, regardless of religion, caste, colour, sexual orientation, etc, Sachin Kalbag, Mid-Day editor

Thousands of adverts are carried in India's hugely popular newspaper matrimonial pages in a time-honoured tradition in which potential spouses are sought and vetted by families.

Preference for higher castes such as the Brahmin group Iyer is often specified in India's entrenched social class system.

Harish Iyer said like most Indian mothers, his was "pretty concerned" about finding him a partner and planning a wedding.

"She thinks I need to settle down as I am growing old," the 36-year-old said, adding he has so far received six responses to the advert, which he said was the first of its kind published in India's matrimonial pages.

"Parents are equally concerned about the future of their children, whether they are gay or not."

Support for LGBT

But he said the English language Times of India and DNA newspapers declined to publish the advert for legal reasons, while the Hindustan Times did not give a reason, after his mother approached all three dailies last week.

"Editorially they show support for LGBT rights but when it comes to actually walking the talk, they hide behind the law," Iyer told AFP news agency.

The Supreme Court restored a colonial-era ban on homosexuality in 2013, a decision that stunned rights campaigners and the gay and lesbian community.

Although prosecutions for same-sex activity have been rare, the gay community says it faces significant discrimination as well as harassment from the police in socially conservative India.

The Hindustan Times declined to comment on the advert, while a DNA spokesman could not be contacted for comment.

A Times of India senior employee in the classifieds section denied refusing the advert, saying the paper's legal team advised changing the word groom to "companion" to comply with the law.

"We are talking to them and will publish it," the employee who declined to be named said.

Mid-Day editor Sachin Kalbag said his paper had no problem with the advert. "We believe that human rights should be applicable to all, regardless of religion, caste, colour, sexual orientation, etc," Kalbag said in a statement emailed to reporters.