Pakistani investigators are glossing over the role of the army in the transfer of nuclear technology to Iran and other countries, a report in the New York Times said on Friday.
The Pakistani army had tight control over the country's nuclear programme.
For the past week senior government and intelligence officials, speaking anonymously, have steadily disclosed details of a deepening inquiry into what seems to have been the transfer of Pakistan's nuclear technology to other countries in late 1980s and early 1990's, the report said.
Their version of events, expected to be released publicly this weekend, blames the country's nuclear scientists, including Abdul Qadeer Khan, the father of Pakistan's nuclear bomb, for selling technology for personal gain.
But one issue rarely addressed by officials of the military-led government is the extent to which the inquiry has examined the role Pakistan's powerful military may have played in the sale or sharing of nuclear technology, the report said.
In interviews this week with the Times, retired Pakistani civilian and military officials, former American diplomats and proliferation experts said the country's government appeared to be glossing over evidence that senior military officials might have approved the sales.
More recent reports of proliferation, including allegations that the governments of President Pervez Musharraf and former Prime Minister Benazir Bhutto shared nuclear technology with North Korea, are also being given 'short shrift', they said.
The officials and analysts emphasised that they had no proof that the army was involved, but wondered why Pakistani investigators had not questioned any senior army officials.
George Perkovich, a proliferation expert at the Carnegie Endowment for International Peace, in Washington, was quoted as saying that Musharraf, who seized power in 1999, was trying to appease American demands for an investigation, while not angering the army, his base of support.
"The problem for Musharraf is that people in the army would know about this," Perkovich said. "And he wants to protect his club."
One focus of suspicion is General Mirza Aslam Beg, commander of Pakistan Army from 1988 to 1991, the paper quoted American analysts as saying.
Robert B Oakley, who served as the US ambassador in Islamabad from 1988 to 1991, said that Gen Beg told him in the spring of 1991 that he was discussing nuclear and conventional military cooperation with Iran's Revolutionary Guards.
"He said he had a good conversation with the Revolutionary Guards about nuclear cooperation and conventional military assistance," Oakley said. "Iran was going to support Pakistan with conventional military aid and petroleum and the Pakistanis would provide them with nuclear technology."
In an interview with the Times this week, Gen Beg denied ever sharing nuclear technology with Iran. But he did confirm that he proposed that Islamabad adopt a doctrine of 'strategic defiance' involving an alliance between Pakistan, Iran and Afghanistan.