The beginning of 2004 saw revelations of a Pakistan-based black market, selling nuclear-weapons technology to foreign governments during the 1990s. Almost a year later questions remain about the extent of the network and allegations that Pakistan's military may have played a role.
Buhary Syed Abu Tahir says one day in the mid 1990s, Iranian couriers came to his room in Dubai and handed him $3 million in cash, stuffed into suitcases.
The money was a payment for centrifuges used to make weapons-grade uranium.
Mr. Tahir, a Malaysian businessman originally from Sri Lanka, told Malaysian police in February that he had been a point man for a worldwide nuclear weapons black market run by Pakistani scientist Abdul Qadeer Khan.
Mr. Khan is a metallurgist credited with leading Pakistan's development of nuclear weapons. Many Pakistanis consider him a national hero.
In February, however, Mr. Khan admitted to a stunned nation that he had sold nuclear technology and material to Iran, North Korea, and Libya.
While Mr. Khan was pardoned for his nuclear proliferation activities, Pakistani authorities have confined him to his home and questioned his associates for possible ties to the operation.
Pakistan's Foreign Ministry spokesman Masood Khan says the probe has managed to roll up Abdul Qadeer Khan's network.
"We did focus on a particular nucleus, a particular network, which had connections with the international black market," said Mr. Khan. "We have dismantled that network, and we have neutralized that nucleus."
But some question whether all the facts of the case have been uncovered.
In November, the New York Times quoted a Central Intelligence Agency report as saying Mr. Khan had provided Iran not only with centrifuges, but also with detailed blueprints for bomb construction.
Pakistan has dismissed the report as exaggeration based on hearsay.
Authorities in South Africa in September uncovered an alleged branch of the Khan network that supplied centrifuges to Libya.
Libya has since renounced its nuclear weapons research, although Iran and North Korea remain in a stand-off with the international community over their own nuclear programs.
The United Nations' International Atomic Energy Agency has expressed concern that Mr. Khan may have passed weapons technology to other nations or groups.
The IAEA is negotiating with Pakistan for permission to question Mr. Khan and with Malaysia for the right to question Mr. Tahir.
The big question, at least within Pakistan, is whether Mr. Khan acted independently.
Syed Munawar Hasan is the secretary general of the Jamaat-e Islami, a religious party that is part of Pakistan's main political opposition alliance.
He says that given the scale of the network, Mr. Khan could not have acted without the knowledge of Pakistan's army.
"Without the connivance or without the patronage of the army, it is just impossible that an individual or a few scientists might have done all those things," he said.
He says Mr. Khan has been sacrificed to appease the United States and other foreign powers concerned about nuclear proliferation.
Mr. Munawar insists authorities should have gone beyond minor scientists and low-ranking officials in their investigation.
"Whosoever was the army chief, he should be debriefed."
A nuclear physicist at Pakistan's prestigious Qaid-e Azam University, Pervez Hoodbhoy, agrees. He adds that the military and the government are too careful about their nuclear weapons to have not known about Mr. Khan's activities.
"Nothing could have taken place without the consent and without the full knowledge of the government," he said. "There is very little doubt of that, given the level of security at the nuclear installations."
The Pakistani government says it has found no evidence to date of any high-ranking involvement in the scandal. But a senior Pakistani official said privately that the investigation is still continuing.
But Mr. Hoodbhoy, who is a leading anti-nuclear activist, says he believes the government will not allow any top officials or senior military officers to be implicated in the case.
He adds that even if the Khan network is finished, proliferation in general will remain a serious danger to the world, both inside and outside Pakistan.
"It is not contained, and I think that although we may have apprehended one of the actors in this whole drama, it is going to be with us for this century, perhaps for all time to come,"said Mr. Hoodbhoy.
He says major nuclear powers, such as the United States, need to address the problem, not only by protecting against proliferators, but also by halting their own nuclear weapons research.