The Flandreau Santee Sioux tribe is suing South Dakota over the state's interpretation that contractors working on an expansion of the Royal River Casino are required to pay contractor excise taxes to the state.

The Argus Leader reported that the lawsuit alleges it's an intrusion into tribal sovereignty and is conflicting with U.S. laws that regulate commerce on reservations.

"The economic burden and the intrusion into tribal sovereignty interfere and are incompatible with the federal and tribal interests in promoting tribal self-government, self-sufficiency and economic development," the lawsuit said.

The lawsuit is the latest clash between the tribe and the state. The tribe's casino has often been a flashpoint for disputes.

The Flandreau started expanding the casino after Gov. Dennis Daugaard agreed to allow the tribe to double the number of slots it had there. The tribe agreed to increase payments to Moody County to offset law enforcement expenses.

Daugaard's chief of staff, Tony Venhuizen, said the tribe doesn't collect the contractors' excise tax.