While Khan was hailed as a national hero in Pakistan for helping make the country a nuclear-armed state, he was viewed by many in the West as a villain.
In the United States, Khan was best known for selling nuclear technology to nations such as North Korea and Iran. In 2004, at the urging of the US, Pakistani authorities placed Khan under house arrest.
Khan was released in 2009, but his movements in and out of the country were still severely curtailed by the country’s security agencies.
The US State Department said that year that Khan had run an “extensive international network for the proliferation of nuclear equipment and know-how that provided ‘one stop shopping’ for countries seeking to develop nuclear weapons.”
According to the State Department, this network’s actions had “irrevocably changed the proliferation landscape and have had lasting implications for international security.”
By Sunday afternoon, tributes had started pouring in for Khan. Pakistan’s Prime Minister Imran Khan tweeted he was “deeply saddened by the passing of Dr A Q Khan.”
“He was loved by our nation (because) of his critical contribution in making us a nuclear weapon state. This has provided us security against an aggressive much larger nuclear neighbor. For the people of Pakistan he was a national icon,” Khan said.
Pakistan’s Information Minister Fawad Choudhry said in a statement that Khan’s “services for the nation and his contributions for strengthening Pakistan’s defense will always be remembered.”
Interior Minister Sheikh Rasheed Ahmed tweeted that Khan’s funeral ceremony will be held at Islamabad’s Faisal Mosque.