The father of Pakistan's nuclear bomb, Dr Abdul Qadeer Khan, and four other scientists have confessed to sharing nuclear technology with Iran, Libya and North Korea, according to reports.
A 12-page report carrying the confessions has been submitted to President Pervez Musharraf, the reports said.
Khan, 66, was sacked as a government adviser on Saturday to "facilitate" the probe.
On Friday, Pakistan Interior Minister Faisal Saleh Hayat told the local Pakistani media: "There is no evidence against Dr A Q Khan and he is not a suspect as yet."
He added, "We are questioning a number of scientists and some of them are suspects, but Dr Khan is not amongst them."
Khan was the kingpin of a nuclear bazaar where the highest bidder was sold nuclear weapons technology, sources allege.
Whether Khan was acting on his own, or at the behest of key military figures within the Pakistani establishment, has yet to be determined.
Last week, Pakistani diplomatic sources claimed Bhopal-born Khan spent $1 million in gifts and preparations for his two daughters' weddings.
Pakistani opposition figures told rediff.com that Khan, who is compared by his well wishers to Albert Einstein, had been gifted a villa on the Caspian Sea and access to exclusive caviar fishing rights by Iran in exchange for vital information about uranium enrichment technology.
Then, one of Khan's former Dutch colleagues, who worked with the Pakistani scientist at the exclusive FDO laboratories in Amsterdam, told rediff.com how Khan
Last Thursday, Pakistani diplomatic sources, comparing Khan to a "Karol Bagh lala", detailed the metallurgist's purchase of a $400,000 Teflon marquee for one of his daughter's weddings as well as lavish gifts of BMWs and houses for his daughters and sons-in-law.
No questions were asked about Khan's lifestyle, his frequent trips abroad -- always first class -- and his lengthy periods of residence under an assumed name at some of the world's most expensive hotels.
Successive heads of Pakistan's Inter-Services Intelligence ignored allegations of financial impropriety until 1990, when Lieutenant General Shamshur Rahman Kallu prepared a report for the attention of the then prime minister Benazir Bhutto.
The report gathered dust until fresh investigations were ordered on the instructions of ISI chief Lieutenant General Mahmoud Ahmad, who handed his findings over to Musharraf in 2001.
Late last year, unable to ignore the mounting evidence of Khan's lifestyle, Musharraf confronted Khan to ask why he had breached Pakistan's trust.
In the unlikely event of his ever being prosecuted, he would reveal the names of those within the upper ranks of the Pakistani army who collaborated with him in his nuclear adventures.
But the turmoil around Khan and his activities has also thrown up evidence of how much some of Pakistan's younger scientists resent his bagging all the credit for his adopted country's nuclear achievements. His fiery temper and his willingness to spend up to Rs 50 million in publicizing his own achievements has not helped either.
In one recent interview, he was asked about the benefits of being 'The' Dr Khan.
He replied: 'If I escort my wife to the plane when she is flying somewhere, the crew will take notice of who she is and she will receive VIP treatment from the moment she steps on the plane. As for me, I can't even stop by the roadside at a small hut to drink chai without someone paying for me. People go out of their way to show the love and respect for me. It is very gratifying.'
Asked when he last paid for dinner, Khan said in the same interview, 'It's been a long time, I can't remember, but I have never tried to take undue advantage of who I am. Once, I was leaving the VIP lounge at an airport, and the security guard asked to see my VIP lounge card. I didn't scream and wave my arms and say 'Don't you know who I am?'
'I just took my card out of my pocket and showed it to him, that man was just doing his job, and that wasn't a problem for me at all. His supervisor did come and yell at him though, he waved his arms and said 'Don't you know who this is? This is Dr Qadeer Khan!'
With Inputs from Shyam Bhatia