Parliament has strongly criticised the government for ordering documents destroyed in a case of Swiss engineers suspected of involvement in a nuclear smuggling ring.
A control committee said that the reasons the government gave for doing so were not convincing and that briefings given to members of parliament were not sufficient. Destroying the documents had also compromised an investigation.
Claude Janiak, head of the delegation, said on Thursday that the government was wrong to do so but it had acted under pressure. He did not elaborate.
Urs and Marco Tinner, along with their father, were arrested starting in 2004 on suspicion of aiding Libya's atomic ambitions through a trafficking ring run by Abdul Qadeer Khan, the founder of Pakistan's nuclear programme.
In November 2007, the cabinet ordered the case documents destroyed, saying it was in the interests of international security. The documents reportedly included designs for nuclear warheads.
It is widely believed the Tinners worked as undercover agents for the United States intelligence service and that Washington asked Bern to destroy the documents.
In a documentary that aired Thursday evening on Swiss television, Urs Tinner claims he tipped American spies off about a Libyan nuclear programme.
The father, Friedrich, and brother Urs were released from jail by December 2008.
The Federal Court announced on Thursday that Marco Tinner would now be granted bail for SFr100,000 ($88,260).