Police have launched an investigation after a shocking homophobic rant on the London Underground was captured on camera.

A Tube passenger filmed the abuse as he tried to reason with the man on a journey home from a New Year's night out at about 5am.

It is claimed that the row started after someone on the same journey was wearing drag and subjected to abuse.

In a Facebook post sharing the video, Ryan Mahon says he stepped in, which led to him subjected to abuse himself.

During the short clip, the man gestures at the person in drag and repeatedly says: "That's immoral. That's wrong.

"You dirty people. God created us to have woman and recreate, you f***ing nasty germ. you rotten person."

Cameraman Ryan tries to argue that there's nothing wrong with being gay, but is sworn and shouted at.

British Transport Police (BTP) confirmed on Saturday (January 2) that they have seen the video and are investigating the incident, which they describe as 'completely unacceptable'.

'Sickening this kind of abuse still happens'

In his Facebook post, Ryan wrote: "Unfortunately, on the way home I witnessed an absolute idiot shouting abuse at a drag queen on the tube.

"I then made the heinous crime of sticking up for her and this video shows what happened

"Luckily, having an amazingly open family, incredible friends and being born and raised in such a multi-cultural city as London this is the first time in the five years since I came out that I've had to deal face-to-face with such homophobic behaviour.

"However, it's sickening to think that this kind of abuse still happens in today's society when there is no place nor any need for it."

A BTP spokesman said: "We have been made aware of a video on social media which appears to show a man making homophobic comments and threats of violence towards passengers on a London Tube train.

"Officers are viewing the footage and making enquiries to establish the full circumstances of the incident and when and where it took place.

"This is completely unacceptable behaviour and we are asking anyone who recognises the man involved to contact British Transport Police on 0800 40 50 40, or text 61016, quoting reference 146 of 2/1/2016.