The Trump Organization's finance boss, Allen Weisselberg, has reportedly been granted legal immunity in the probe into Michael Cohen.
US media reported that he was summoned to testify earlier this year in the investigation into Cohen, Donald Trump's longtime former lawyer.
Cohen pleaded guilty on Tuesday to handling hush money for Mr. Trump in violation of campaign finance laws.
Mr. Weisselberg, Chief Financial Officer, is the latest to get immunity.
On Thursday, it emerged that David Pecker, head of the company that publishes the National Enquirer tabloid, was also given immunity.
Mr. Weisselberg is reportedly mentioned on a tape secretly recorded by Cohen in 2016 in which a hush money payment to an alleged lover of Mr. Trump is discussed.