TREMPEALEAU COUNTY, WI -

La Crosse County District Attorney Tim Gruenke is investigating allegations that a Trempealeau County official used his office to advance his own sand mining business interests.

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.

Gruenke was appointed special prosecutor on the case because the Trempealeau County district attorney recused himself due to a possible conflict of interest. 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.

The Trempealeau County Board is meeting Monday night to discuss a moratorium on permitting of industrial sand activities.