BERN, May 23: The Swiss government destroyed sensitive evidence in a high-profile nuclear smuggling case linked to Libya’s now-abandoned effort to build an atomic bomb because of security reasons, Switzerland’s president said on Friday.

The documents formed part of a criminal case against three members of a Swiss family accused of involvement in the “nuclear smuggling ring of Abdul Qadeer Khan”.

President Pascal Couchepin, speaking publicly on the matter for the first time, said federal prosecutors discovered that the information contained in the files was “explosive” for Switzerland’s security and foreign policies. The government in November ordered the files to be destroyed, but did not make the decision public at the time.

“There were detailed construction plans for nuclear weapons, for gas ultracentrifuges to enrich weapons-grade uranium as well as for guided missile delivery systems,” Couchepin told reporters in the Swiss capital.

The documents were destroyed under the observation of the UN’s International Atomic Energy Agency, he said.

Couchepin, who holds Switzerland’s yearly rotating presidency, read out a prepared statement and declined to answer questions about the case.

Swiss media have reported that the files were secretly ordered destroyed by the government last year after pressure from the United States, which was concerned that its efforts to clamp down on nuclear smuggling might be compromised.

Zurich daily Tages-Anzeiger reported on Friday that Urs Tinner, one of the three accused, was recruited by US intelligence while he was part of Khan’s network.

The US embassy in Switzerland declined to discuss the matter. “The embassy does not comment on intelligence issues,” spokeswoman Lisbeth Keefe said.Zurich weekly SonntagsZeitung said in March that information provided by Tinner led to the 2003 seizure of the German-registered freighter “BBC China,” which was carrying components for a uranium enrichment plant from Dubai to Libya. The ship’s interception prompted Libya to admit his country’s nuclear weapons plans and agree to abandon them.

Tinner, 43, has been in custody since 2004 while Swiss prosecutors prepare their case against him.—AP