Pakistan's interior minister, information minister and top intelligence officials have flatly rejected reports that Osama bin Laden had been captured.
"It is totally baseless. There is no truth in it," Information Minister Mr Sheikh Rashid said.
Iranian radio reported bin Laden had been arrested and was in the custody of Pakistani intelligence agents. It cited the Islamabad-based leader of the small Islamic party, Pakistan Awami Tehreek, which has one seat in the national assembly.
The leader, Mr Agha Murtaza Poiya, later said he was citing second-hand claims.
The report quoted Mr Poya saying the arrest would not be announced untilwar had started against Iraq.
"We have got no evidence to suggest that Osama bin Laden is in Pakistan. I don't understand why people keep coming up with concocted stories," Interior Minister Mr Faisal Saleh Hayat said.
And a senior security official closely involved in the hunt for al-Qaeda fugitives in Pakistan dismissed the report as "incorrect."