RAIB investigators are still analysing evidence from the crash.

Data recorders from the trains, sometimes known as “black boxes”, have been recovered.

Investigators have also obtained CCTV footage, signalling data and recordings of radio communications.

Initial findings showed the Corby service had been travelling at about 76mph (122km/h) before its brakes were applied nine seconds before impact.

The maximum speed for trains in this area is between 125 mph (201 km/h) and 100 mph (161 km/h), though this depends on the type of train.

At the point of impact, the train was travelling at about 49mph (79km/h).

Prior to the collision it had passed two yellow signals, which warn a driver they should be prepared to stop at a red signal.

The train then passed a red signal shortly before colliding with the stationary train.