Scientists have uncovered the strongest evidence yet in the debate of whether people are ‘born gay’.

The largest ever study into the existence of a so-called ‘gay gene’, conducted by NorthShore Research Institute, looked at 409 sets of gay brothers in an effort to finally put the debate to rest.

The study identified two genetic regions – Xq28 an 8q12 – which seemed to be correlated to homosexuality in men.

Lead scientist Alan Sanders said that the work “erodes the notion that sexual orientation is a choice” – but said the study also did not identify a single gene which was the direct cause of homosexuality.

He stressed that a variety of factors – including genetics, upbringing and environment play a part in developing sexual orientation, which is complex and emerges over time.

Though some remain sceptical, neuroscientist Simon LeVay told the New Scientist: “His study knocks another nail into the coffin of the ‘chosen lifestyle’ theory of homosexuality.”

“Yes, we have a choice in life, to be ourselves or to conform to someone else’s idea of normality, but being straight, bisexual or gay, or none of these, is a central part of who we are, thanks in part to the DNA we were born with.”

Richard Lane of Stonewall told the Independent: “While some people may choose to focus on the continuing debate of whether people are born gay or not, we’ll continue to focus on making sure everyone has the same rights and opportunities regardless of who they love.”