A TUBE passenger launched an unprovoked attack on a father in front of both the victim's girlfriend and young daughter on a train between South Harrow and Rayners Lane.
The British Transport Police (BTP) released a still from a station platform closed-circuit television camera in a bid to help solve the incident that happened at 11.05am on Sunday December 11.
Officers said the victim, his girlfriend and his daughter were travelling on an eastbound Piccadilly line train when a man boarded at Rayners Lane station and soon started verbally abusing him before physically assaulting him.
The father tried to protect himself and his young family before the three managed to get off the train at South Harrow. The victim suffered cuts and bruises.
The attacker also got off the train at South Harrow and was seen to exit the station and board a bus from a stop in Northolt Road, South Harrow.
BTP Detective Constable Keith McEwen, the investigating officer, said: “We have made local enquiries but have been unable to identify the attacker.
“We have reviewed CCTV and are keen to speak to the man shown in the image as we believe he may be able to help us with our investigation.
“This was an unprovoked attack and must have been very distressing for the man’s young family to have to witness and I am appealing for anyone who may have seen the attack or who knows the man in the image to come forward.”
The man in the CCTV image is described as black and about 6ft 5in tall.
n Anyone who recognises the man in the image or who has any information about this incident is asked to call British Transport Police (BTP) on 0800 40 50 40, quoting background log number B17/LUA of 22/12/2011, or call Crimestoppers anonymously on 0800 555 111.