A man, believed to be from Welling, is wanted for questioning by police after two women were groped in separate incidents on a train to Dartford.
Police last month issued an image of a man they believe has key information about a 35-year-old woman being inappropriately touched on a busy commuter train Victoria to Dartford at 5pm on February 28.
During the journey a man stood behind the woman and inappropriately touched her. It is thought the man got on the train at Denmark Hill and left the service at Welling station.
They are now appealing over a second incident on April 14 at around 5pm, and want to trace the same man.
Detective Constable Andy Parkinson said: "The 37-year-old victim was travelling on the 4.39pm London Victoria to Dartford train in one of the front carriages, having boarded at Lewisham.
"A few minutes later she became aware of a man standing behind her and touching her inappropriately. She confronted the man and he walked off down the train, leaving at Welling.
"There were lots of people on this train and I am confident many of them will be able to help us with information about what took place."
Despite police enquiries, including searches conducted at stations and on trains, a media appeal and liaison with police, the man pictured remains unidentified. It is believed he could reside in the Welling area.
Anyone with information should contact British Transport Police on 0800 40 50 40, or text 61016, quoting SSUB/B4 of 17/04/14. Information can also be passed to the independent charity Crimestoppers on 0800 555 111.