The scene near Twyford Station on Sunday was attended by a land ambulance and an air ambulance but a man in his fifties was pronounced dead at the scene. The victim has not yet been identified.

An investigation into the incident, which happened at 11.30am near Milley Bridge, has now been launched by the Rail Accident Investigation Branch (RAIB).

A spokesperson for the British Transport Police (BTP) said: "BTP is assisting the RAIB in its investigation of this fatality.

A First Great Western spokesman said the incident caused severe disruption with more than 70 services either delayed or cancelled and some trains held up for more than two hours while emergency services dealt with the situation.