India's Supreme Court is scheduled to hear a final petition against a law that criminalises homosexuality.

Three senior judges would revisit a 2013 ruling that reversed a landmark 2009 Delhi High Court order which had decriminalised homosexual acts.

According to Section 377 of the Indian Penal Code (IPC), a 153-year-old colonial-era law, a same-sex relationship is an "unnatural offence".

There has been a very vocal campaign to decriminalise homosexuality in India.

Activists say police and authorities often misuse the law to harass homosexuals. Under this law, a same-sex relationship is punishable by a 10-year jail term.

On Tuesday, the court will hear a "curative petition" which is meant to "cure" any earlier court order perceived as a "miscarriage of justice".

In its 2009 ruling, the Delhi High Court had described Section 377 as discriminatory and said gay sex between consenting adults should not be treated as a crime.

The ruling was widely and visibly welcomed by India's gay community, which said the judgement would help protect them from harassment and persecution.

However, several political, social and religious groups petitioned the Supreme Court to have the law reinstated, and in 2013 the top court upheld the law, saying it was up to parliament to legislate on Section 377.

However, an Indian MP's bid to introduce a private member's bill in the parliament to decriminalise gay sex failed.

Shashi Tharoor who also started a petition on Change.org over the issue, which has more than 40,000 signatories, said "it is time to bring the Indian Penal Code into the 21st Century".

In deeply conservative India, homosexuality is a taboo and many people still regard same-sex relationships as illegitimate.