NASHVILLE (AP) — Ned McWherter, one of the most powerful Tennessee Democrats during his quarter century in public life, never got caught up in any of the FBI undercover investigations that pushed another governor out of office early and led to several prison sentences and suicides for others in his party.

The Associated Press obtained the 217-page FBI file on McWherter, who died in April, through a Freedom of Information Act request.

A 1995 background check into McWherter's life and political career ruled out any involvement in an undercover investigation that rocked state government while he was governor.

"Although Mr. McWherter was surrounded by individuals who were involved in the bingo scam ... he at no time was a subject, witness, or a target in the Rockytop investigation," according to the memo.

The FBI's investigation was named "Rocky Top" after the popular state song. It found bingo operators were using state charters of legitimate Tennessee charities to run gambling operations in the late 1980s.

The probe eventually led to a prison sentence for Democratic state Rep. Tommy Burnett. The investigation also looked Secretary of State Gentry Crowell's handling of bingo regulation and led authorities to looking into other activities by legislator Ted Ray Miller. Both Democrats committed suicide during the investigations.

Burnett was majority leader while McWherter was speaker, while Crowell served as Democratic caucus chairman and was elected by lawmakers to his first term as secretary of state in 1977.

State Sen. Randy McNally became the key insider in the Rocky Top investigation after reporting suspicions to the FBI. The agency asked McNally to wear a recording device at Legislative Plaza, and he captured evidence of offers to pay cash for votes, including a $10,000 offer from a lobbyist who was also the state's former chief bingo regulator.

McNally, an Oak Ridge Republican who is now chairman of the powerful Senate Finance Committee, said he was unsurprised that the FBI found McWherter had no involvement even though others in state government at the time "walked a fine line between what was criminal and what was not, and sometimes they crossed over that line."

"I think he was certainly above that," McNally said. "In my dealings with him, he always acted ethically and came down on the side of what was legal."

The materials released by the FBI were collected as part of a background check after President Bill Clinton nominated McWherter for the U.S. Postal Service Board of Governors. Friends, neighbors and associates interviewed by FBI agents made almost entirely positive statements about the former governor. While one interviewee said he once saw McWherter consume a quart of scotch, he said he showed "no sign of excessive use of alcohol."

One exception to the nearly uniform praise was an administrative aide in Secretary of State Crowell's office, whose name is redacted in the records. She alleged that McWherter had ordered several campaign contributions of more than $100 be returned to donors and have them re-issue several smaller contributions to avoid disclosure requirements.

McWherter told investigators that he had a strained relationship with Crowell's aide, including once ordering her off the House floor and telling her "to quit meddling in the legislative process." He said the aide "was absolutely not involved" in any of his campaigns, and he denied any discussion of breaking contributions into smaller increments.

Crowell's top assistant in the secretary of state's office, Mary Sue Wright, was also entangled in the bingo investigation and was identified by investigators as an unindicted co-conspirator. She died in 1998.

The FBI file makes no mention McWherter's activities as House speaker during the tumultuous administration of Gov. Ray Blanton. In 1979, McWherter and then-Senate Speaker John Wilder led an effort to remove the Democratic governor from office three days early amid clemency-for-cash and bid-rigging scandals that sent some of his aides to prison.

Two years later, Blanton was convicted of extortion for selling liquor licenses, though that conviction was overturned after he completed his prison sentence.

McWherter was out of office when the 2003-04 FBI probe known as Tennessee Waltz sent five former lawmakers to prison for influence peddling.

Mike McWherter, who was last year's Democratic gubernatorial nominee, said his father always stressed ethical behavior.

"My father always repeated to me was that he was really not aware of anyone in his administration who had used their position for their own self-interest," McWherter said. "My father was probably the person who set the tone for that.

"He set high standards for himself and was very ethical, and he expected everyone who worked with him to maintain those standards."