Police officers have issued CCTV images of a man they wish to identify in connection with a hate crime incident on a southbound Northern line train between Leicester Square and Kennington.
The incident happened on Saturday 30 January at around 7pm on the southbound train which passed through Waterloo.
BTP PC Elaine Sexton said a short time after boarding the train at Leicester Square the victims were subjected to verbal homophobic abuse by another passenger.
"Two men, both in their forties, were travelling home from central London when a man sitting opposite them began to verbally abuse them using homophobic insults," she said.
The man also threatened the pair with violence before he left the train at Kennington. He caught another southbound train from the Bank branch platform.
"Any hate crime offence is treated very seriously by BTP," added PC Sexton.
"While the two men were not injured, this must have been a very intimidating and unpleasant experience for them."
Anyone who recognises the man in the images or who has any information which may assist the investigation is asked to contact BTP on 0800 40 50 40 quoting incident number 464 of 30/01/2010.