A suspected Russian operative who has worked for years with former Trump campaign chairman Paul Manafort has been indicted for witness tampering, Robert Mueller’s special counsel office announced today.

The individual, Konstantin Kilimnik, is named in a new “superseding” indictment of Manafort which charges both of them with obstructing justice by contacting two public relations executives with whom they had worked on what prosecutors say was a 2012-era scheme to illegally disguise paid lobbying on the behalf of a Russia-backed regime in Ukraine. Prosecutors say Manafort and Kilimnik contacted the associates by phone and messaging apps this year and attempted to convey to them that they should disseminate the (allegedly false) narrative that the lobbying in question did not take place in the United States. (The PR executives are not, at this point, accused of any wrongdoing.) Those accusations were previewed in a Monday filing by the special counsel’s office that seeks to modify the conditions of Manafort’s bail; a hearing on that subject will take place June 15 and could result in Manafort going to jail.

It’s been previously reported that Kilimnik, a colorful Ukraine-born figure who was trained as a translator by the Soviet military intelligence organization GRU, was an individual referred to in other special counsel filings as “Person A.” Mueller’s team has asserted that Person A “has ties to a Russian intelligence service and had those ties in 2016,” while a recent Atlantic story by Manafort expert Franklin Foer suggests that Kilimnik is currently living in Russia. (In any case, to be clear, he has not been arrested by agents of the U.S. Department of Justice. He has denied that he is a Russian spy.)

Mueller is investigating Manafort’s shady past work in Ukraine not just to gain legal leverage against him but to determine whether the Russian figures to whom he was connected there were used as a back channel to the Trump campaign in 2016. For now, despite Kilimnik’s indictment, that question remains unanswered.