Former special counsel Jack Smith, who was involved with probes into Donald Trump, is being investigated by the Office of Special Counsel.

The US Office of Special Counsel, which is supposed to be an independent federal agency, has launched an investigation into Smith over an alleged violation of the Hatch Act, a law that bars certain political activities by government officials.

The probe comes after Republican Arkansas Sen. Tom Cotton urged acting Special Counsel Jamieson Greer to investigate Smith, accusing him of acting in a political manner to undermine Trump in his presidential bid last year.