State Sen. John Ford (search) was placed under house arrest Friday after prosecutors played a video of the lawmaker watching an undercover agent count out $10,000 and an audiotape of him threatening potential witnesses.

The tapes were played at a bond hearing a day after Ford was charged as part of a two-year FBI sting operation nicknamed "Tennessee Waltz." Ford is charged along with four other current and former state lawmakers with taking payoffs, but he alone is accused of threatening to kill witnesses.

U.S. Magistrate Diane Vescobo set bond at $20,000 and ordered Ford to remain under house arrest until his trial.

Ford is the brother of Harold Ford, who served 11 terms in Congress. His nephew, Rep. Harold Ford Jr (search)., has served five terms in Congress and said Wednesday he would run in 2006 for the Senate seat being vacated by Republican Majority Leader Bill Frist.

The videotape shows John Ford across a desk from an undercover FBI agent laying down $100 bills for what U.S. Attorney Tim DiScenza said was a bribe. Ford leans over and the agent asks him if he is counting. Ford says, "I ain't trying to count. I trust you."

In a scratchy Feb. 3 audiotape, Ford tells an undercover informant that he owns a gun and could shoot someone. The informant can be heard laughing, which FBI agent Mark Jackson described as nervous laughter because "the threat sounded legitimate to him."

Jackson said Ford told an agent at a later meeting that "if he caught someone trying to set him up, he would shoot that person, kill them, so that there would be no witnesses."

Ford's attorney, Michael Scholl, suggested the lawmaker was joking with the agent.

"Things are said ... that are meant in a joking manner," Scholl said.

Ford was arrested Thursday as part of a sting operation in which undercover agents created a sham company named E-Cycle Management and posed as executives who asked lawmakers to introduce bills to help their business.

According to the indictments, the lawmakers and two other men took $92,000 to usher bills for E-Cycle through the Legislature. Ford is accused of taking $55,000 between August and April.

The other defendants were released Thursday without posting bond.

Over three decades in the Tennessee Senate, Ford has lost paternity lawsuits, given a political job to a girlfriend, used campaign money for his daughter's wedding and been successfully sued for sexual harassment. The Senate Ethics Committee and a federal grand jury are also investigating $429,000 Ford received from a consulting company with financial ties to the state's Medicaid program.