The second train then forged ahead on the same track in the opposite direction, before the first was able to split off where the line divides into two, according to RND.
The influential daily Sueddeutsche Zeitung also said preliminary investigations showed that the safety system had been manually switched off by a signalling controller who only realised he had made a colossal mistake when it was too late.
Police would not confirm the reports, and a spokeswoman from the transport ministry would also not be drawn.
"All possibilities that could have led to this disaster are being examined. That includes examining the black boxes, looking at what happened on the tracks, speaking with witnesses and signalling workers," said spokeswoman Vera Moosmayer.
"There are no findings yet. The investigations are ongoing.