More on the killing of Hamid Karzai's brother Ahmed Wali's assassination today allegedly by his bodyguards. 

It has been alleged by James Risen of the New York Times and that Ahmed Wali Karzai was a prominent figure in the Afghan drug trade, controlling a significant proportion of heroin or opium.

In meetings with Afghan President Hamid Karzai, including a 2006 session with former US Ambassador to Afghanistan, Ronald E. Neumann, the CIA's station chief and their British counterparts, American officials have talked about the allegations in hopes that the president might move his brother out of the country, said several people who took part in or were briefed on the talks.

"We thought the concern expressed to Karzai might be enough to get him out of there," one official said.

But President Karzai has resisted, demanding clear-cut evidence of wrongdoing, several officials said. "We don't have the kind of hard, direct evidence that you could take to get a criminal indictment," a White House official said.

Ahmed Wali Karzai constantly dismisses the allegations as politically motivated attacks by longtime rival groups in his country.