Abdul Qadeer Khan, lionized at home as the father of Pakistan’s atomic bomb despite admitting he was at the center of a nuclear proliferation ring, died on Sunday at age 85.

The nuclear scientist was admitted to hospital on August 26 after testing positive for COVID-19.

"He was loved by our nation because of his critical contribution in making us a nuclear weapon state," Pakistan's Prime Minister Imran Khan on Twitter.

But A.Q. Khan also confessed to being at the core of an operation that sold nuclear secrets to North Korea, Iran and Libya.

Analysts and United Nations officials have said his illicit network, which specialized in helping countries skirt international sanctions, created the greatest nuclear proliferation crisis of the atomic age.

After a confession on national television to his involvement in selling nuclear secrets, Khan was pardoned by then-president Pervez Musharraf. He remained under house arrest for years in his palatial Islamabad home.

In his confession, Khan said he acted alone without the knowledge of the state officials. Later he said he had been scapegoated.

Musharraf once described Khan's admission of guilt, following a tip-off from the CIA, as the most embarrassing moment of his presidency.

Pakistan never let foreign investigators question Khan, saying it had passed on all relevant information about his nuclear proliferation.