Rinat Akhmetshin, the Russian-American lobbyist who was present at the 2016 meeting at Trump Tower with Trump campaign officials, has provided evidence to a grand jury that is part of special counsel Robert Mueller's Russia investigation, according to multiple reports Wednesday.

Sources told the Financial Times that Akhmetshin, a former Soviet army officer, testified for multiple hours on Aug. 11.

"He went into the court for hours," said one person familiar with the matter. "It can't be fun in the bull's-eye."

When asked to comment on the grand jury appearance, Akhmetshin told the Times, "I don't know what you're talking about ... I'm not commenting on anything." He also said he would provide "full cooperation" when necessary.

A spokesman for the special counsel's office also declined to comment for the story.

Akhmetshin, who claims he was not working on behalf of the Kremlin, was one of several attendees at the July 2016 meeting, which included Donald Trump Jr., former Trump campaign manager Paul Manafort, President Trump's son-in-law Jared Kushner and Russian lawyer Natalia Veselnitskaya.

Trump Jr. helped set up the meeting on premise that Veselnitskaya would provide damaging on Trump's 2016 presidential rival Hillary Clinton. After details of the meeting were revealed earlier in this year, Trump Jr. claimed nothing of substance was offered on Clinton and that the meeting quickly turned to the issue of child adoption.