Khan, the father of Pakistan's nuclear weapons programme, underwent cancer surgery in September 2006 and was hospitalised on Wednesday after he complained of fever and low blood pressure.

"Dr Khan was shifted to his residence after gaining significant improvement in his health," the official Associated Press of Pakistan said quoting unnamed sources.

"Further treatment as required would be provided to Dr Khan at his residence," the sources told APP.

An army statement Wednesday said Khan had been in good health since he was diagnosed with prostate cancer but that on Tuesday "he complained of weakness and was provided immediate medical treatment at home."

Khan fell from grace after he publicly confessed in February 2004 to proliferating nuclear secrets.

He was immediately pardoned by President Pervez Musharraf. But while not officially under detention, Khan has since been forbidden from leaving his house in an upscale area of the capital Islamabad.

Musharraf has refused to allow international investigators to question Khan on the extent of his proliferation activities, saying that Pakistani authorities are capable of the task.