SAN DIEGO -- A federal grand jury indicted three current and former Clark County officials Thursday on charges of conspiracy to commit wire fraud and wire fraud in a sweeping public corruption investigation.

County Commissioner Mary Kincaid-Chauncey and former Commissioner Dario Herrera also face an extortion charge in the 28-count indictment. Lance Malone, (pictured, right), a former commissioner in Las Vegas, faces a federal racketeering charge.

Malone served as a lobbyist for strip club owner Michael Galardi, who has been at the center of the more-than-two-year investigation in Las Vegas and San Diego.

The indictment says Kincaid-Chauncey and Herrera "solicited and accepted money, property and services from Malone."

It accuses them of trying to "conceal payments they received" and using their "public office to further Michael Galardi's interests."

U.S. Attorney Daniel Bogden said during a Thursday news conference that the indictment was significant.

"You have individuals who are attempting to trade votes for money, and that's something we can't tolerate in our community," he said.

Lawyers for Kincaid-Chauncey and Malone weren't immediately available for comment. Herrera's lawyer, David Brown, declined to comment until he had seen the indictment.

Thursday's indictment was the result of a federal investigation involving politicians in Las Vegas and San Diego. The probe became public in May after FBI agents raided Galardi's strip clubs and the City Hall offices of three San Diego city councilmen.

Galardi, 41, has pleaded guilty to wire fraud after a San Diego grand jury indicted him in August. The same grand jury also indicted the three San Diego city councilmen and Malone. All four have pleaded not guilty.

A federal magistrate issued summons for Kincaid-Chauncey, Herrera and Malone. They were ordered to appear Nov. 21 in federal court for an arraignment.

All have denied any wrongdoing.