Mayor Eric Adams’s former chief liaison to the Muslim community was arrested Tuesday on federal witness tampering and destruction of evidence charges that had grown out of the investigation that led to the mayor’s indictment last month.

The liaison, Mohamed Bahi, was charged by the F.B.I. in a criminal complaint in connection with the investigation of illegal contributions made to Mr. Adams’s 2021 mayoral campaign, officials said.

The complaint against Mr. Bahi has significant implications for Mr. Adams. According to prosecutors, a businessman who made straw donations to the mayor on behalf of four of his employees has been cooperating with the investigation. Mr. Adams’s lawyer has previously suggested that the indictment against the mayor was based primarily on the cooperation of one witness, another former aide. But the charges today indicate otherwise.

Initially, the businessman lied to federal investigators, the complaint says, and was urged by Mr. Bahi — who claimed he had spoken to Mr. Adams — to continue doing so.