Alex van der Zwaan, a former Skadden, Arps, Slate, Meagher & Flom associate and son-in-law of the Russian oligarch German Khan, pleaded guilty Tuesday to one charge brought by special counsel Robert Mueller.

Van der Zwaan, a 33-year-old Dutch citizen who was with Skadden’s London office, lied to investigators about his communications with former Trump campaign deputy Rick Gates and an unnamed person, according to court documents made public Tuesday.