Last month, Afghan security forces arrested Salehi for allegedly soliciting a bribe in exchange for impeding a US-backed investigation into a company suspected of shipping billions of dollars out of Afghanistan in the service of government officials, drug smugglers and anti-government fighters.

The revelation that Salehi has received payments from the US spy agency demonstrates the complex relationship Washington has developed with the Afghan government.

'Counter-productive'

George Little, a spokesman for the CIA, would neither confirm nor deny the
reports, but said that speculation about such matters was dangerous.

"This agency - acting in strict accord with American law - plays an essential role in promoting our nation's goals in Afghanistan, including security and stability," he told the Associated Press.

"Speculation about who may help us achieve that is both dangerous and counter-productive."

The CIA has placed many Afghan officials on the payroll over the years, according to Ali Jalali, a former Afghan interior minister.

He said the agency has had deep involvement in Afghanistan for decades, and it would be natural for the CIA to have long-standing "relationships'' with many Afghan leaders.

"You have to put things into perspective,'' he said.

He added that he doubted Karzai would be surprised if Salehi were on the CIA payroll, as alleged.

"When Karzai was fighting against the Taliban, he was supported by the agency, too," Jalali said.

Allegations of corruption and nepotism have dogged the US presence in Afghanistan and such problems undermine support for Karzai's government and foreign nation-building efforts, analysts say.