Investigations have been launched by the ORR, RAIB and BTP following the death of a track worker.
In the early hours of November 6, a 37-year-old man died when he was struck by a train at Stoats Nest junction, between Purley and Coulsdon South stations, on the main line from London to Brighton.
The RAIB said he had been contracted to carry out protection duties in connection with engineering work. This involved placing red lamps and detonators on two tracks (the up and down slow lines).
After completing this duty, at around 00:27, the staff member was walking south along the down slow line when he was struck by a passenger train, which had crossed over from the down fast line to the down slow/Redhill line at Stoats Nest junction, and was travelling at around 70mph.
Emergency services attended but the man was pronounced dead at the scene.
At the time of the incident, BTP Detective Inspector Darren Gough said: “We are doing all that we can to establish the circumstances behind what happened, and we have specialist officers supporting his family through this difficult time.”
John Halsall, Network Rail’s managing director for the south east, added: “This incident is a terrible tragedy involving a member of the railway family. Our thoughts are with our colleague’s loved ones and members of the team who worked with him.”