Audio reveals exchanges between Spain train operators and drivers moments before deadly crash

The audio recordings were published by several Spanish news outlets including El Pais and RTVE.

In one, a control centre operator is speaking to the driver of the Renfe train, which was having some technical difficulties.

After some exchanges, the control operator tells the driver: "Continue your journey and then proceed under [Lateral Signalling Block], at normal speed with normal operation."

The driver replies: "At normal speed?" To which the controller answers: "Yes."

The Lateral Signalling Block is a back-up or alternative train system used when the automatic signalling or data transmission system fails.

The driver of the stationary Iryo train says in another audio recording that communication with the train-control system has been lost, and it is not moving.