NEW YORK - The NYPD’s top officials have endorsed the department’s surveillance of Muslims and even top-secret missions abroad. According to the author of a new book, though, the FBI says these efforts produced “no intelligence of any value.”

That’s what reporter Ronald Kessler has found, at least, and he’s dug deep to get to the bottom of the NYPD’s controversial surveillance tactics that were first uncovered by the Associated Press in recent months. Earlier this year it was discovered that the NYPD had been conducting clandestine surveillance over Muslims and collecting intelligence everywhere from local markets to mosques and even in cities abroad. Kessler investigated that program to put together his forthcoming book, “The Secrets of the FBI,” and in an excerpt just released by the author, he writes that even one of America’s biggest intelligence agencies is up in arms over the NYPD’s actions.

Kessler writes that the efforts under former FBI Director J. Edgar Hoover “not only trampled on Americans’ rights but often failed to focus effectively on real threats such as spies and terrorists.” Decades after Hoover’s death, however, Kessler says that those merits are alive and well, but not with the FBI. Even though it’s arguably not part of their job, the NYPD has adopted controversial techniques and policies that the author compares to the practices put forth by Hoover.

“In an unprecedented move, Michael B. Ward, the special agent in charge of the FBI’s Newark office, went public to say that the New York surveillance tactics were not an effective form of intelligence gathering and were in fact harming the fight against terrorism by fomenting distrust among New Jersey’s Muslims,” Keller writes.

Elsewhere in his excerpt, which he says will appear as an epilogue to the paperback edition of his book, slated to hit stores on August 8, Keller writes that FBI officials have shunned the NYPD. Despite widespread anger against the agency going beyond their jurisdiction, though, Keller says that complaints from the Justice Department are not being fully addressed.

“Last March, Attorney General Eric Holder Jr. said the Justice Department would review the matter,” Keller says, but not before noting, “What has never come out is that the FBI considers the NYPD’s intelligence gathering practices since 9/11 not only a waste of money producing no intelligence of any value but a violation of Americans’ rights.”

Keller even adds that, according to FBI officials that anonymously made comments to him during his investigation, the NYPD is even going beyond what the federal bureau would do.

“The NYPD has been sending undercover operatives to political meetings,” one source says. “The FBI would not be allowed to do those kinds of things. We stay away from the Intelligence Division because we know what they are doing would not pass the test with FBI oversight authorities.”

Just last week, a Freedom of Information Act request for a phone call placed with emergency services in New Brunswick, New Jersey ended up with the recording being released to the Web, revealing that law enforcement agents across the river from Manhattan were unaware that the NYPD was leaving the Big Apple to do surveillance across the river. New York Mayor Michael Bloomberg and NYPD Commission Ray Kelly have both defended the police department’s actions.