A federal judge appointed by President Donald Trump has rejected a challenge to Robert Mueller’s authority.

U.S. District Judge Dabney Friedrich upheld the special counsel’s appointment on Monday in a challenge by a Russian firm, Concord Management and Consulting, report the National Law Journal and Politico.

Concord Management was among 13 Russian nationals and three Russian groups accused of trying to influence the 2016 election.

Friedrich is the fourth federal judge to turn aside challenges to the special counsel, according to Politico. Friedrich cited the previous judges’ rulings.

Concord had contended that Mueller’s powers were so vast that he didn’t qualify under the appointments clause as an “inferior officer” who could be appointed by Deputy Attorney General Rod Rosenstein. Rather, Mueller should have been appointed by the president and confirmed by the Senate, Concord had argued.

Federal judge appointed by Trump rejects challenge to Mueller’s authority