Geneva -- The Swiss government vowed Wednesday to destroy sensitive documents related to an alleged case of international nuclear smuggling, rejecting demands from lawmakers to reverse its decision.

"There are no grounds ... to reverse its decision, which takes into account in a measured manner the needs of the prosecuting authorities and Switzerland's international engagements," the government said in a statement.

"From the point of view of security policies, it is imperative that the most sensitive documents, which detail the making of nuclear weapons, are destroyed," it added.

Switzerland in 2008 revealed that three Swiss engineers accused of allegedly smuggling nuclear secrets to Libya possessed detailed plans on how to make such weapons.

The government said it destroyed some of these documents in November 2007 "to prevent them falling into the hands of a terrorist organisation or non-authorised state."

The move sparked an uproar as judges and lawmakers said it would compromise investigations into the three Swiss engineers' involvement.

However, authorities revealed in December 2008 that there were more case documents at the Swiss federal prosecutor's office, and a parliamentary commission sought to have them preserved.

Reports have claimed that the family of engineers was recruited by the CIA to help stop attempts by Libya and Iran to develop nuclear weapons, and that Swiss and US authorities cooperated after they were arrested.

The New York Times reported in October that the documents were destroyed due to pressure from the US spy agency, which feared its ties with the engineers would be exposed.

On Wednesday, the government found that the parliamentary commission which sought to stop the destruction of the documents "certainly did not have the competence... to issue such orders to the government."

It said that it would replace the most sensitive documents by "an insert" that "gives an indication of the contents of the missing pages," noting that this "conforms to the demands of security policies."

AFP / Expatica