The magazine Stern reported on Wednesday that MPs have been infuriated by supposedly widespread spying at the national railway operator conducted by Network Deutschland – the same surveillance company used by Deutsche Telekom to secretly monitor its workers.

The magazine said it has documentary evidence that Deutsche Bahn collected the personal information of at least 1,000 employees and several hundred of their spouses, and gave that information to Network Deutschland.

The so-called Operation Squirrel even included the copying of computer hard drives of several employees without their knowledge, the monitoring of their internet use and even their bank accounts – and those of their spouses. The spying was allegedly designed to protect Deutsche Bahn against the potential corrupt practices of some staff.

But MP Anton Hofreiter, Green transport spokesman, said he was appalled, demanding: “Deutsche Bahn must absolutely explain this.” He said he was calling Bahn representatives to answer questions in front of the transport parliamentary committee.

Deutsche Bahn has admitted that certain investigations were carried out, but says its operations were nothing compared with previous privacy scandals such as the one at Deutsche Telekom.

Alexander Dix, the Berlin data protection representative with responsibility for Deutsche Bahn, told the magazine he saw the Bahn had broken the rules on data protection, and suggested the case could even result in criminal prosecution. “We are checking to see if we should bring the public prosecutor into this,” he said.