"We are working with Pakistan to come to the bottom of this ring of proliferators," Mohamed ElBaradei told Reuters at the World Economic Forum in Davos.
"I hope we should be able in the next few weeks to come to grips with the extent and nature of that ring and dry it up as soon as possible," he added.
ElBaradei said on Thursday anti-proliferation efforts were under great stress because of what he called a black-market network that was trading in weapons technology.
"What we are seeing is a very sophisticated network of black-market proliferators, people who are selling equipment, material underground. We're still very much in the process of investigating this network."
Pakistan says it began questioning its nuclear scientists, including the father of its atomic bomb, Abdul Qadeer Khan, after the UN nuclear agency began investigating possible links between the Pakistani and Iranian nuclear programmes.
Musharraf said similar allegations had been made against European individuals and countries, adding that any Pakistani found to be involved would be treated as "anti-state elements".
"The Pakistani government has never, and will never proliferate," he said in Davos.