From The Washington Post:
Back in the early ’60s, Khan was a low-paid postal inspector in Karachi, known for demanding bakshish, or bribes, according to Adrian Levy and Catherine Scott-Clark, who write for the London Guardian. Then he visited a U.S.-sponsored exhibition on Eisenhower’s vision of “Atoms for Peace” and, ironically, had an atomic vision of his own: a Pakistani bomb. He headed to Holland to study metallurgy, married a South African woman of Dutch descent and got a job at a subcontractor for Urenco, a consortium of European governments that operates a top-secret uranium enrichment facility on the Dutch-German border.
“An expatriate Muslim from a South Asian country known to be in pursuit of the bomb, Khan should have stuck out,” Levy and Scott-Clark rightly note in Deception. Instead, the Dutch gave him a limited security clearance and, before long, access to highly classified designs for an enrichment centrifuge. He did little to hide his translating, copying and photographing of the plans, scribbling data in a black notebook that his co-workers grew to know well. It was these designs that he provided first to his own country and later to others.
More here.