Pakistan's controversial nuclear proliferator AQ Khan could not have acted alone, "without the awareness of the Pakistani government," the Swedish Weapons of Mass Destruction Commission has said in a report.
Coming from a commission headed by Hans Blix, a former chief of the International Atomic Energy Agency (IAEA), the report challenges the contention of Pakistan's Musharraf regime and could fuel a fresh controversy by US think tanks who have constantly alleged official complicity in whatever Khan did.
A report on Blix's findings, made public in Washington, was carried without comment by the Daily Times newspaper on Thursday.
Among the beneficiaries of Khan's proliferation, as per Western media reports, are North Korea, Iran, Libya and the radical Islamist network headed by Osama bin Laden.
North Korea and Iran have recently denied that their nuclear programmes are based on anything received from Khan.
Khan pioneered Pakistan's nuclear weapons programme in the 1970s and 1980s. He is under house arrest since January 2004 and is currently recovering in Islamabad after prolonged illness and a surgery.
President Pervez Musharraf has said that he detained Khan after being confronted by the Central Intelligence Agency (CIA) with evidence that Khan had continuously passed on nuclear data and designs.
But Musharraf has said that successive governments had no knowledge, no role in proliferation and that Khan had 'confessed' to having done on his own, without authorisation.
Pakistan has allowed IAEA, the UN's body to monitor nuclear activities, to interrogate Khan, but has thwarted pressures by the US to meet Khan.
The Swedish commission has focused on nuclear know-how reaching non-state operators, particularly terror network.
The commission has said that as far as it was aware, nuclear weapons had never been stolen or transferred from arsenals of states. The threats posed by existing nuclear weapons relate in the first place to the risks of deliberate use.
It notes that high representatives of nuclear-armed states have recently alluded in "precisely calculated ambiguity" to a readiness actually to use nuclear weapons.
Additional dangers could arise as a result of accidents, miscalculations, faulty intelligence and theft of unauthorised use.
Addressing the possibility of terrorists acquiring nuclear weapons, it said nobody could make a nuclear weapon without fissile material and the technical knowledge to design and manufacture a device. The first task is more difficult than designing a weapon.
"The basic information to design a crude nuclear device is publicly available. To produce the plutonium or highly enriched uranium needed to make a nuclear weapon is difficult and expensive.
It requires the kind of infrastructure that is likely to be available only to states. There is a risk that security weaknesses could allow terrorists to steal enough material," the Blix commission has said.