A prosecutor is investigating allegations that a county supervisor in western Wisconsin used his office to advance his own sand mining business interests.

The Star Tribune of Minneapolis reports the clash in Trempealeau County, just across the Mississippi River from Winona, is the latest ethics controversy to surface in the region's burgeoning silica sand industry.

Trempealeau County Board Supervisor David Suchla is accused of threatening a high-level county administrator to keep silent about a business relationship that Suchla had with a large Texas-based company interested in mining silica sand in the supervisor's district for use on hydraulic fracturing.

LaCrosse County District Attorney Tim Gruenke says he'll decide over the next few weeks whether to prosecute.

Suchla confirms he's in the sand business, but denies any self-dealing as a public official.