Secret information on counter-terrorism shared by foreign governments might have been compromised by massive data theft by a senior IT technician for the NDB, Switzerland's intelligence service.
Intelligence agencies in the US and Britain are among those who were warned by Swiss authorities that their data could have been put in jeopardy, said one of the sources, who asked for anonymity.
Swiss authorities arrested the technician suspected in the data theft last summer. He was later released while a criminal investigation by the office of Switzerland's Federal Attorney General continues, according to two sources familiar with the case.
The suspect's name was not made public. Swiss authorities believe he intended to sell the stolen data to foreign officials or commercial buyers.
Swiss news reports and the sources close to the investigation said that investigators believe the technician downloaded terrabytes, running into hundreds of thousands or even millions of printed pages, of classified material from the Swiss intelligence service's servers onto portable hard drives.
He then carried them out of government buildings in a backpack.
One of the sources familiar with the investigation said that intelligence services such as the US Central Intelligence Agency and Britain's Secret Intelligence Service, also known as MI6, routinely shared data on counter-terrorism and other issues with the NDB.
Swiss authorities informed US and British agencies that such data could have been compromised, the source said.
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