"The report is groundless," Information Minister Sheikh Rashid told AFP, in response to Tuesday's New York Times report.

Rashid said Pakistan was a responsible nuclear power and had a foolproof export control regime in line with its non-proliferation obligations.

He said Pakistan had already started a process to investigate allegations some scientists may have indulged in passing on sensitive technology to Iran in an individual capacity.

The process was launched after Pakistan received information from International Atomic Energy Agency (IAEA) and it was being pursued intensively to ascertain the facts.

"As far as the Pakistani government is concerned it has given 400 percent assurances and its credibility is unquestionable," the minister said.

The New York Times report named Pakistan as the source of centrifuge design technology that helped Libya make big strides in its nuclear program in the past two years.

The report quoted US officials in Washington and other Western experts as saying they had no evidence Pakistani President Pervez Musharraf's government -- which vowed after the September 11, 2001 attacks that such transfers have stopped -- knew about the episode.

But it reported that the "main aid to Libya appears to have come since those attacks, suggesting that Pakistani scientists may have continued their trade even after the explicit warning."

Pakistan has recently launched an investigation after the International Atomic Energy Agency asked it to look into the suspicions that some individual scientists may have passed on some technology to Iran.

Following the IAEA letter Pakistani authorities last month took in Farooq Mohammad and Yasin Chohan, directors of Pakistan's key uranium enrichment facility Kahuta Research Laboratories (KRL), for questioning.

A government spokesman last month said the father of the country's nuclear programme and former KRL chairman, Abdul Qadeer Khan, had also been questioned.

The White House earlier also made clear it did not view the New York Times report as proof Musharraf was not living up to his pledge to halt Pakistani proliferation activities.

"We fully expect President Musharraf and the government of Pakistan to follow through on those assurances," spokesman Scott McClellan said.

But he added: "We recognize that it's always difficult to control the activities of rogue individuals whose motives are personal gain."

Musharraf has been a key ally in the US campaign against terrorism in South Asia, and there has been intense concern in Washington for his safety, after he narrowly escaped a pair of recent assassination attempts.

WAR.WIRE