CARSON CITY -- The Nevada Supreme Court will be asked today by slot machine giant International Game Technology to dismiss a whistle-blower's claim that IGT filed false tax returns and owes up to $30 million in back state taxes.

Justices have combined the case with an appeal filed by Attorney General Brian Sandoval seeking dismissal of lawsuits filed by a Chicago law firm that says some big companies are evading taxes on Internet sales.

Under Nevada's whistle-blower law, both former IGT employee Jim McAndrews and the law firm of Beeler, Schad & Diamond could get a cut of any taxes recovered as a result of their litigation.

But if IGT and Sandoval's office prevail, the state Taxation Department would have the job of seeking any lost tax revenue -- and McAndrews and the Beeler law firm wouldn't get a percentage of any recovered funds.

Washoe County District Judge Peter Breen in July rejected efforts by IGT and Sandoval to have McAndrews' case dismissed. Breen said he didn't want to undermine the 1999 whistle-blower law, which gives people with inside knowledge about such cases a percentage of any amount eventually collected by the state.

The politically connected slot machine company then asked the Supreme Court to overrule Breen, saying that the back-taxes issue should be handled by the Taxation Department. It says it never filed false tax returns.

Sandoval made a similar argument in the tax dispute involving the Beeler law firm and major retailers such as Amazon, Borders, Target, Toys "R" Us, Wal-Mart, Hallmark Cards and Petsmart.

While Sandoval's office didn't sign onto the IGT dismissal petition, he had made the same argument in Breen's court: Nevada law says tax collections are exclusively within the jurisdiction of the Taxation Department.

Whistle-blowers are entitled to as much as 50 percent of recovered tax revenue, although McAndrews' lawyer, John Bartlett, has said 20 percent is more common. He also said that if McAndrews' $30 million claim held up, a treble damages clause could push the amount due the state to $90 million.

McAndrews, hired by IGT to work on tax matters, alleged that IGT and Anchor Coin Co. were involved in a joint venture and since 1997 filed false sales and use tax returns with the state on sales and leases of slot machines and slot components. Anchor later was acquired and merged into IGT.

The Beeler law firm contends sales and use taxes are due on items ordered over the Internet and shipped to Nevada if companies have stores in the state. Attorney Dan Reaser, representing Amazon and Borders Group, said his clients maintain there are no taxes due.

Reaser said Beeler has filed similar lawsuits in at least two other states. He said the Nevada attorney general sought to have the Beeler lawsuits filed in Las Vegas dismissed. Clark County District Judge Valorie Vega refused and permitted the legal action to go forward.

The Nevada Taxpayers Association has joined the case as a friend of the court, saying the issue should be determined state Taxation Department.