Members of The Dave Matthews Band, who have a reputation for clean-cut sensitivity, found themselves in a messy situation this week, as they were charged with improperly flushing sewage from their tour bus.

The band’s tour bus driver dumped a tankful of human waste from a bridge onto a Chicago tour boat, Illinois Attorney General Lisa Madigan alleged.

Both the driver, Stefan Whol, and the band were charged.

The complaint, filed late on Tuesday, said Whol was driving the bus across a bridge over the Chicago River when the waste was released.

It sloshed through a grate in the bridge and spattered dozens of passengers on the upper deck of a boat conducting an architectural cruise.

Some of the passengers suffered nausea and vomiting following the August 8 incident, and five went to a local hospital for tests.

A publicist for the band issued a statement on Tuesday saying: “Our driver has stated that he was not involved in this incident. We reserve any judgment until we see the evidence.”

Whol was on his way to pick up a band member at a hotel on Chicago’s swanky Michigan Avenue at the time.

The complaint, filed in Cook County Circuit Court, accuses Whol and the band of water pollution, discharge of a contaminant into a waterway and creating a public nuisance.

The state is seeking $70 000 in civil penalties.

The band was in Chicago to play shows in East Troy, in the neighbouring Midwestern US state of Wisconsin.