The CIA deceives its own employees by distributing internal memos that contain incorrect information about clandestine drone strikes and other operations, according to a new report from The Washington Post.

The tactic, known as "eyewashing," is employed by inserting fake information about operations or agency sources into a regular internal memo, and then sending it on to a large group of staff. Another message is then sent to a smaller subset of the first group, telling them to ignore the previous message in lieu of the real information included in the second message.

"It's just another form of compartmentation," a former senior U.S. intelligence official told the Post. "The classic use of an eyewash is if you have a garden-variety source and all of a sudden he gains access to truly sensitive information. What you might do is have a false communication saying the guy got hit by a bus and died. The large number of people aware of this source suddenly think he is dead. But the continuing reporting on that source and from that source gets put into a very closed compartment that few would know about."

The Senate uncovered a few cases of suspected eyewashing during its investigation into the CIA's controversial enhanced interrogation program. The practice was omitted from the committee's public report but remained in the classified version.

In one example, top CIA officials told agents in Pakistan that they were not authorized to carry out a potentially deadly operation against al-Qaida's Abu Zubaida. They then sent a second message to a smaller group of agents telling them that they could proceed with the mission, according to officials who reviewed the classified report.

In another case, the CIA issued a cable saying a senior al-Qaida leader had been killed in a tribal conflict. But in reality, he was killed by a drone strike at a time that the agency didn't want its drone capabilities exposed to hundreds of analysts and other employees at the agency's Counterterrorism Center, according to the Post.

The Post's source expressed concern over there being no way to distinguish eyewash cables from legitimate memos, meaning that the false information could mislead the CIA's inspector general, Congress and historians.

It's a crime under federal law for a government employee to conceal, cover up, falsify or make a false entry in an official record, and legal experts told the Post that they were not aware of any exemptions for the CIA.

The report comes shortly after the Pentagon decided against demoting retired Army Gen. David Petraeus for illegally loaning his biographer and mistress eight binders containing highly classified information relating to war strategy, intelligence capabilities and identities of undercover agents, reported CBS News. Petraeus resigned from his position at the CIA in 2012 and pled guilty to a misdemeanor count of unlawful removal and retention of classified information, according to the Justice Department.