New Delhi: India's top court scrapped a colonial-era ban on gay sex on Thursday in a landmark judgment that activists hope will uphold the right to equality.

Gay sex is considered taboo by many in socially conservative India, and was reinstated as a criminal offence in 2013 after four years of decriminalisation.

A five-judge bench in India's Supreme Court was unanimous in overturning the ban.

"Any consensual sexual relationship between two consenting adults - homosexuals, heterosexuals or lesbians - cannot be said to be unconstitutional," said the Chief Justice of India, Dipak Misra, as he read out the judgement.