MOSCOW — The Russian lawyer who met with Trump campaign officials in Trump Tower in June 2016 on the premise that she would deliver damaging information about Hillary Clinton has long insisted she is a private attorney, not a Kremlin operative trying to meddle in the presidential election.

But newly released emails show that in at least one instance two years earlier, the lawyer, Natalia V. Veselnitskaya, worked hand in glove with Russia’s chief legal office to thwart a Justice Department civil fraud case against a well-connected Russian firm.

Ms. Veselnitskaya also appears to have recanted her earlier denials of Russian government ties. During an interview to be broadcast Friday by NBC News, she acknowledged that she was not merely a private lawyer but a source of information for a top Kremlin official, Yuri Y. Chaika, the prosecutor general.

“I am a lawyer, and I am an informant,” she said. “Since 2013, I have been actively communicating with the office of the Russian prosecutor general.”