A key member of the House Intelligence Committee says the controversial brother of Afghanistan President Hamid Karzai regularly helps U.S. intelligence -- but should not be considered an American spy.

Rep. Mike Rogers of Michigan, ranking Republican on the subcommittee overseeing Terrorism/Human Intelligence, Analysis and Counterintelligence, regularly visits Afghanistan, where his brother, an Army general, has also served.

Rogers said in an interview that Ahmed Wali Karzai, widely reported to be protecting the heroin trade in southern Afghanistan, "cooperates" with U.S. intelligence, but is not a controlled agent.

"There's a difference between being an intelligence asset and somebody who cooperates," said Rogers, a former FBI agent. "'Asset is an overstatement ... He is a public official who cooperates ... He cooperates when he's talked to -- that's different than an asset."

Wali Karzai, a major power in Kandahar, where he heads the provincial council, is cagey about what he tells the Americans, Rogers and other U.S. officials say.

But a former top NATO official in Afghanistan said that the president's brother wasn't omniscient.

"He had his finger on a lot of things, but not everything," he said, on condition of anonymity.

"If I wanted to get information on Kandahar, I'd go into the presidential palace and talk to a couple of [President] Karzai's boys from that area, and then I might take that to Wali and ask him about it," the former official said.

The depiction of Karzai as a valuable U.S. intelligence asset was aired in a Sept. 14 story about the Taliban's threat to in Kandahar by the Washington Post's prize-winning Rajiv Chandrasekaran.

"Several U.S. lawmakers, including Vice President Biden when he was chairman of the Senate Foreign Relations Committee, have urged the president to dismiss his brother from the [Kandahar Province] council," Chandrasekaran wrote.

"But U.S. and Canadian diplomats have not pressed the matter, in part because Ahmed Wali Karzai has given valuable intelligence to the U.S. military, and he also routinely provides assistance to Canadian forces, according to several officials familiar with the issue."

According to The New York Times, "Several American investigators said senior officials at the DEA and the office of the Director of National Intelligence complained to them that the White House favored a hands-off approach toward Ahmed Wali Karzai because of the political delicacy of the matter."

But the former top NATO official said hard evidence linking Wali Karzai to the drug trade was lacking.

"I was always told Karzai was the biggest problem because he was involved with of drugs," he said, "but I couldn't prove it."

Nevertheless Kandahar's citizens have repeatedly blamed Wali Karzai as the center of corruption in the region, where the Taliban are resurgent.

President Karzai could make life difficult for the U.S. in Afghanistan if his brother were forced from power or arrested, Rogers said.

The congressman ticked off a number of responses the Afghan leader could take: postponement of a status-of-forces agreement that the U.S. has been pursuing; releasing people from prison; demanding NATO troop withdrawals from particular areas; and even threats to make regional power-sharing deals with the Taliban.

U.S. anti-corruption advocates will have more leverage to deal with Wali Karzai after the presidential election results are settled, Rogers maintained.

But for now, "We certainly need the president to be with us," he said.

"That would be hard if we're hauling off his brother to a detention center."