You don't hear much these days about a Minneapolis mystery once dubbed "a City Hall Watergate." But the apparent bugging of feisty Council Member Steve Minn's office 17 years ago remains one of city's most puzzling political capers.

The discovery of the recording device in a third floor ceiling vent at City Hall, and the investigation that followed, had all the intrigue of "All The President's Men" — minus the secret rendezvous in a shadowy parking lot. It involved two reporters, ethical questions about a trip to Japan, and a mayor's office that seemed to know too much.

MPLS made a Freedom of Information Act request for the FBI's files on the matter and recently received 87 pages of heavily redacted notes.

It started in October 1995 when Minn, the council's most conservative member, began inquiring about who was paying for a trip that Mayor Sharon Sayles Belton was taking to Japan. Two reporters, Star Tribune's Kevin Diaz and KSTP's Jay Kolls, were talking to Minn about stories regarding the trip. When Kolls confronted Belton about it in a heated exchange, one of her aides told him, "We know you've been in Minn's office," according to FBI notes.

The aide, Mary Pattock, made a similar comment to Diaz, who advised Minn that there may be a leak in his office but that he did not want to discuss it over the phone. Minn then looked around his office, noticed a hole in a ceiling tile and pulled out a Radio Shack wireless microphone with a "wire stuck in the air vent."

Minn didn't want it in the newspaper, but Diaz said the newspaper had decided to do a story. Minn told the FBI he thought it might be a hoax, but reported it to police after consulting with an attorney friend. The front page headline the next day read: "Council member's office bugged."

The FBI files reveal some details that were not publicly disseminated in the days that followed. Among the new revelations is this tidbit from the FBI's interview with Belton, who left office in 2001 Pattock [see update]:

"She believed it would be ridiculous to [plant the device] to learn political secrets as there are no secrets in City Hall," the notes say.

The FBI also concluded that unprotected handling of the device by three police officers, Minn and two others led to "contamination" that ruled out obtaining fingerprints. The files show the Minneapolis police purchased an identical device and placed it in an air vent, only to find that it likely had "almost zero range" and was probably "worthless" for transmitting conversations.

The bug was nonetheless sent to FBI offices in Quantico, Va., for testing. A forensics exam concluded the $20 device's range was less than 25 feet. A clip on the back allowed it to attach to a tie or lapel. Installing a new battery, the examiner found its transmissions could be picked up on "any FM radio within its transmitting range."

Several people contacted the FBI with tips, including one who believed "it is possible that Minn planted the bugging device in his office to get sympathy."

The FBI also wanted to interview Diaz, but a Star Tribune representative said the feds would need a court order — they "could read the newspaper" if they wanted more details. The paper also would not honor a federal grand jury subpoena. A prosecutor believed the paper's rep was mistaken, but told an agent that "the facts in this case" did not justify the ordeal of taking the newspaper to court.

Since examinations revealed "it is highly unlikely that the device could ever be effectively used," the local assistant U.S. attorney declined to prosecute the case.

In an interview last week, Walt Dziedzic, a City Council member at the time, said the bug was discovered during a period when the federal government was closely monitoring city politics.

"When that bug was there, I thought maybe they had something to do with it…. Not necessarily the FBI, but the federal government," Dziedzic said.

Minn, now a local developer, believes the whole ordeal probably got more attention than it deserved.

"At the end of the day, conjecture and circumstance conspired to suggest a conspiracy that could never have been proved," Minn said. "And there wasn't any important information to be gleaned."

Here are the FBI files: