Pakistan's disgraced nuclear scientist, AQ Khan, who admitted illegally transferring technology overseas, is in a stable condition after a heart scare.
AQ Khan confessed last year to leaking nuclear secrets
A presidential spokesman said Dr Khan, 69, had suffered chest pains on Tuesday but denied he had had a heart attack.
Dr Khan undertook a check for blocked arteries and was given the all-clear.
Dr Khan is seen by many Pakistanis as a hero for founding the nation's nuclear industry but has been under virtual house arrest since February 2004.
Treated at home
Maj Gen Shaukat Sultan, military spokesman and media secretary for President Pervez Musharraf, said Dr Khan was now "absolutely fine and stable".
"He did not have any heart attack," Gen Sultan said.
Dr Khan is still seen as a hero by many Pakistanis
He said Dr Khan had been declared fit and well after an angiogram at a military hospital in Rawalpindi on Friday.
Information Minister Sheikh Rashid Ahmed said Dr Khan was still at the Armed Forces Institute of Cardiology along with his family members.
Dr Khan has been confined to his home since his public confession early last year that he illegally transferred nuclear technology to countries including North Korea, Libya and Iran.
He was given a pardon by President Musharraf because of his services to the nation's nuclear industry.
The government has always denied any involvement in the leaking of the technology.
This year it confirmed Dr Khan had supplied nuclear centrifuges - which can be used to enrich uranium for nuclear weapons - to Iran.
Dr Khan has not been allowed to receive visitors and international investigators probing global nuclear proliferation have not been allowed to question him.
President Musharraf has said the discovery of the Khan network was the most embarrassing episode in his political career.
Former CIA director George Tenet described AQ Khan as being at least as dangerous as Osama Bin Laden.