Senior officials said Islamabad would look into any fresh evidence if it emerged but described the article in US weekly Time as baseless and a rehash of previous reports.

"This is not correct," foreign ministry spokesman Masood Khan told reporters at a weekly briefing when asked if Khan, the father of Pakistan's atomic programme, had sold technology to fellow Muslim nation Saudi Arabia.

"The allegation has been made several times in the past, but this is part of a disinformation campaign. It is baseless (and) does not have any substance," he added.

"It is a rehash of several speculative stories which have appeared in the media in the recent past."

Abdul Qadeer Khan has been under effective house arrest since he appeared on Pakistan state television in February 2004 and took full responsibility for passing nuclear technology to Iran, Libya and North Korea.

Pakistan's President Pervez Musharraf gave him a conditional pardon and has said that no government or military body was involved in the scandal.

But the military leader has steadfastly refused to allow the US or the International Atomic Energy Authority (IAEA) to interrogate Khan.

Time magazine, citing a source in Pakistan's defense ministry, said Khan had also played a bigger role in helping Iran and North Korea with their nuclear programs than had been previously disclosed.

"US intelligence officials believe Khan sold North Korea much of the material needed to build a bomb, including high-speed centrifuges used to enrich uranium and the equipment required to manufacture more of them," Time said.

Masood Khan said Pakistan's probe into the scientist's nuclear black market was not over and insisted that Islamabad had done its duty to the international community.

"We have not closed investigations. If new fresh leads emerge we would like to check them out and if fresh evidence is furnished to us we would like to look into that," he said.

"We have done more than any other country in the world. There are other countries... it was alleged that they were involved in the international black market. We are yet to see if they are looking for skeletons in their cupboards."

Earlier Information Minister Sheikh Rashid also branded the Time report as "baseless and without facts".

The minister and the spokesman both denied claims that 16 cylinders of uranium hexafluoride gas used for uranium enrichment were missing from the country's main enrichment facility, Khan Research Laboratories (KRL).

"Our inventory is complete and nothing is missing from KRL," Rashid said.