The co-author of Deep Throat's book will lash out at The New York Times this Sunday for hiring Richard Nixon counsel John Dean to review it.

John O'Connor, who helped Mark Felt write "A G-Man's Life: The FBI, Being 'Deep Throat,' and the Struggle for Honor in Washington," based upon manuscripts written by Felt before he began showing signs of dementia, shot off a letter blasting Dean.

"It would be hard to imagine a reviewer more biased than Dean," O'Connor writes. "He was convicted of a crime and disbarred as a result of both Felt's investigation of Watergate and his role as 'Deep Throat.'"

Felt was deputy director of the FBI even as he was feeding information about the infamous Watergate burglary to Bob Woodward at The Washington Post. The case led President Nixon to resign, as chronicled in Woodward's book with partner Carl Bernstein, "All the President's Men."

"The book ... deals sneeringly with Dean's lack of integrity," O'Connor adds, "and Dean himself has written two books assessing the identity and motives of Deep Throat, both of which were proven embarrassingly wrong."

Dean defends himself, and in a back and forth, the two men argue over much, including Felt's belief that it was Dean and John Ehrlichman who blocked his appointment as director of the FBI. "We were out of the White House at the time," Dean had written in his review. But O'Connor parries that Nixon passed Felt over on April 27, 1973, and Dean and Ehrlichman didn't resign until April 30.

In a small postscript, New York Times Book Review editor Sam Tanenhaus admits, "The Book Review should have encouraged [Dean] to be more explicit about his dealings with Mark Felt during the Watergate controversy."