Pakistan seeks court backing to probe scientist AQ Khan
Pakistan's government has filed a court application to investigate disgraced nuclear scientist Abdul Qadeer Khan.
Officials cited reports in the Washington Post newspaper in which it was alleged that Dr Khan was involved in proliferation to Iran and Iraq.
Dr Khan rejected the claims and denied that he had spoken to the media.
The application from Pakistan's government comes ahead of talks in Washington on a possible civilian nuclear deal with the United States.
"We want to question Dr Khan about this interview, which has revealed sensitive information about Pakistan's nuclear programme," the government said in its application to the high court in Lahore.
The court had been hearing a petition filed by Dr Khan who accuses the government of restricting his movement, despite a court order last August freeing him from house arrest.
He was detained in 2004, following a televised confession that he had been involved in international nuclear proliferation.
The BBC's Syed Shoaib Hasan says Pakistan's government has been keeping close tabs on the former head of the country's nuclear programme since his release.
"We want to learn who is passing on such information to foreign newspapers," the government's application to the court said on Monday.
"Such information has a direct bearing on the security of Pakistan's nuclear programme."
The interviews that have upset the government were published on 10 and 14 March in the Washington Post.
Dr Khan has denied giving them. Speaking on Monday to local newspapers and TV channels in Pakistan, he said the information had been fabricated.
The petition happened to be filed as Pakistan's military chief and foreign minister landed in the United States.
They are to begin talks with US officials on 24 March on a possible civilian nuclear deal between the two countries.