Citing unnamed current and former "intelligence officials familiar with the operation," the newspaper said the program called "The Brain Drain" was ordered by the White House in 2005 in hopes of undermining Iran's nuclear weapons program.

The effort achieved only limited success because fewer than six well-placed Iranians have defected, and none has been able to provide good information on Tehran's nuclear program, the report said.

The paper did not identify the defectors. But it said there was speculation of CIA involvement in the apparent defection of a former Iranian deputy defense minister, Ali Reza Asgari, who went missing last February during a visit to Turkey.

Potential defectors have not been approached by the CIA directly, The Times pointed out, citing a former US intelligence official. Rather, the spy agency used other contacts it has cultivated inside Iran, the report said.

Intelligence gathered through the program provided much of the information for last week's National Intelligence Estimate that argued that Iran had halted its nuclear weapons program in 2003, the paper said.