By Zaffar Abbas
BBC correspondent in Islamabad
Pakistan has denied press reports that disgraced nuclear scientist Abdul Qadeer Khan has had a heart attack.
Dr Khan is under military detention at his residence
A military spokesman said doctors had examined Dr Khan over the weekend but added it had been a routine check-up.
Earlier, a report in the prestigious Pakistani newspaper Dawn had described Dr Khan's condition as critical.
The father of Pakistan's nuclear programme was pardoned earlier this month after admitting leaking nuclear secrets to Iran, Libya and North Korea.
Pakistani military spokesman Major-General Shaukat Sultan described Dr Khan's condition as "hale and hearty".
According to the Dawn newspaper, a medical team with cardiac machines had been sent to Dr Khan's residence - where he is under detention - after he suffered a heart attack over the weekend.
Quoting hospital sources, the report said Dr Khan had been complaining of pain in his left hand since he was interrogated by the authorities about his role in nuclear proliferation.
The report described Dr Khan's condition as critical, but the military spokesman said it was not true.
Major General Sultan said after medical examination doctors declared that he had no heart-related illness.
Dr Khan and 10 other scientists and officials in Pakistan's nuclear establishment have been named by the government as part of a group involved in selling nuclear information and technology to other countries.
Since then he has confessed his guilt, and appealed for mercy.
President Pervez Musharraf subsequently granted him a conditional pardon, which officials say is subject to his continued co-operation with the investigations into the proliferation scandal.
The whereabouts of other detained scientists and officials are not known.