Assistant U.S. Attorney John H. Durham, leader of the investigation, recently granted immunity from prosecution to a CIA lawyer who reviewed the tapes prior to their destruction to determine if they varied from written accounts of the interrogations, two people familiar with the matter told The Washington Post in a story published Thursday.
The sources said the act of granting immunity could indicate the case is nearing its final stages.
The CIA lawyer, John McPherson, could appear before a grand jury later either this month or April, the sources told the Post. CIA lawyers have been critical to the investigation because they offered advice to agency personnel about the handling of the video tapes.
A U.S. official cautioned about reading too much into the latest developments in Durham's investigation.
"Durham runs a tight ship, and there haven't been any real leaks out of his investigation," the official said. "People should, for that extremely compelling reason, be very careful about believing anything billed as inside scoop from the Durham inquiry. It's probably, at best, gossip and rumor."
Jose A. Rodriguez, an ex-chief of the CIA's directorate of operations who was key to the destruction of the 92 tapes in November 2005, has not offered testimony to investigators, the Post said.
Durham's team is trying to determine whether the destruction of the tapes amounts to a crime.