Concord Management and Consulting LLC hired Washington lawyers Eric Dubelier and Katherine Seikaly, according to court filings in the case, which was brought by Special Counsel Robert Mueller.

The appearance of Dubelier and Seikaly indicates that Mueller’s office is facing a fight on a new front, which could shed more light on the Russian efforts to interfere in U.S. politics. The special counsel’s office is getting set to try President Donald Trump’s former campaign manager Paul Manafort on tax and bank fraud charges later this year.

Since Mueller filed a sweeping indictment in mid-February against 13 Russian individuals and three companies — which include Concord Management and Concord Catering — there’s been no activity in the case. Most expected that no one would appear to defend against the charges.

Dubelier has beaten the Justice Department in past skirmishes. In 2012, he won an acquittal for a former secret service agent at the center of a Foreign Corrupt Practices Act prosecution known as the “Africa Sting” case. The Justice Department had charged Dubelier’s client and others with conspiracy in a case where undercover agents, posing as representatives of an African government, solicited bribes in return for lucrative arms contracts.

Shortly after the acquittal, the government’s entire case collapsed, resulting in a major embarrassment for prosecutors.

These Are the Russians Accused of Meddling in the 2016 Election

Deputy Attorney General Rod Rosenstein announced Mueller’s charges in February, alleging that workers at a St. Petersburg, Russia, troll farm set out in 2014 to sow discord in the U.S. political system, ultimately by supporting Trump and disparaging Hillary Clinton.

The case is U.S. v Concord Management and Consulting LLC, 18-cr-00032, U.S. District Court, District of Columbia (Washington).