Embattled Texas Attorney General Ken Paxton now faces a potential bribery probe, triggered by a six-figure donation to his legal defense fund from a business executive enmeshed in a recently settled Medicare fraud suit.

Kaufman County District Attorney Erleigh Wiley is investigating the $100,000 donation by Preferred Imaging CEO James Webb, which came a year before his company paid $3.5 million to settle charges it overbilled the government for services, the Dallas Morning News reported Thursday.

Paxton has raised more than $500,000 over the past two years to battle charges that he violated state law by selling securities without properly registering authorities and failed to disclose he was being paid by the company, Servergy Inc., he was asking investors to buy shares in.