Prosecutors said on Tuesday that “human error” probably lead to the deadly train crash, which claimed 11 lives in Southern Germany.
Prosecutor Wolfgang Giese said that his office has opened a criminal investigation against the 39 year old dispatcher for negligence leading to the incident.
"If he had complied with the rules ... then there would have been no collision between the trains," Giese said.
"There is no evidence of technical problems... Our investigation shows that this was human error with catastrophic consequences," he added.
According to the prosecutors, the dispatcher whose duty includes directing traffic sent a wrong signal to the trains.
Following, the dispatcher realising his mistake, he tried to make an emergency call to the machinists. However, he failed to prevent the accident in which two trains crashed head-on, while they were travelling at about 100km/h (60mph), east of Bad Aibling.
The prosecutors are waiting for the results of the test to complete the investigation.
The police also tested the dispatcher to learn whether he was under the effect of alcohol or drugs during the accident, but the results were negative.
The worker also admitted on Monday his share in the incident saying that it was not a deliberate action.
"What we have at the moment is a terrible error in this particular situation," fellow prosecutor Juergen Branz said.
German authorities had said that the rail system had been designed to prevent such incidents.
However, German media outlets reported that a signalling worker had manually switched an automatic signalling system off to let the eastbound train -which was running late- go past.
If the dispatcher is convicted, he could face at least five years in prison.
The crash occurred, around 7 am local time on Tuesday near the spa town of Bad Aibling, about 60 kilometres (37 miles) southeast of the Bavarian capital of Munich. During the clash there were 150 passengers from the two trains on board.