A man and a woman were seen "tussling" on railway tracks today moments before they were hit by a packed commuter train, police said.
The pair, thought to be boyfriend and girlfriend, died instantly when they were hit at Harlow Mill, Essex, at about 8am.
Police said an investigation had been launched.
Detective Chief Inspector David Shipperlee, of the British Transport Police, said: "Raised voices were heard. It would appear from CCTV evidence that the couple were on the tracks and they were both pulling at each other.
"They were standing in the southbound lane and they were seen on the CCTV to be tussling. It's not clear at this stage who was pulling whom and for what reason.
"It may be the male was trying to pull the female away, as was suggested by one witness."
Police covered two areas of track about 300 yards apart as scene-of-crime officers combed the area.
The bodies were taken away in a private ambulance at about 3pm.
Mr Shipperlee confirmed relatives of the dead woman had visited the scene.
A middle-aged woman sobbed as she was driven away in a Range Rover with a middle-aged man, woman and a young child.
Mr Shipperlee said formal identification of the dead bodies had yet to take place although both were thought to be local.
He added: "We think they are boyfriend and girlfriend."
Mr Shipperlee said there were about 300 people on board the train, a 6.18am service from King's Lynn, Norfolk, to London Liverpool Street.
A small number were also waiting on the platform at the time of the incident, Mr Shipperlee said.
Bradley Pressman, 53, who runs a car dealership next to the station, said there had been three other fatalities on the line already this year.
He added: "Apparently the man and woman were seen arguing on the platform prior to the train arriving. The police were here very quickly. There were people who were on the platform who would have seen what happened."Reuse content