Prosecutors say the Suffolk County Sheriff used his post to get stock in a cannabis company — and then demand the return of his $50,000 investment.

Tompkins was charged with pressuring owners of a cannabis company by threatening to revoke a partnership with his office, which was central to the company's licensing application.

Suffolk County Sheriff Steve Tompkins pleaded not guilty to corruption charges Thursday at federal court in Boston, with his lawyer stating “the facts simply will demonstrate that he was charged with a crime he did not commit.