President Hamid Karzai of Afghanistan has admitted his office received secret payments from the United States, but says the amounts were small and used legitimately.
He was responding to a report by the New York Times that the CIA sent suitcases stuffed with cash to the president's office on a regular basis.
The paper said tens of millions of dollars "came in secret" and cash was given on a vaster scale than previously thought.
Mr Karzai said the money was for projects such as helping the sick. He added that the money had been delivered to Afghanistan's National Security Council, which is part of the president's office, during the last 10 years.
The New York Times report said: "Wads of American dollars packed into suitcases, backpacks and, on occasion, plastic shopping bags have been dropped off every month or so at the offices of Afghanistan's president."
It quoted Khalil Roman, who was Mr Karzai's chief of staff from 2002 - 2005, as saying the cash was referred to as "ghost money".
"It came in secret, and it left in secret," Mr Roman is quoted as saying.