All four were arraigned, while an indictment handed up Wednesday was announced.
Randell Hutchinson, who had been with the Hamtramck department for 17 years, was suspended Thursday. Hutchinson allegedly told a member of the Highwaymen club about a wiretap, The Detroit News reported.
David Tomlan, who was fired by the Garden City department in 2006, was also charged. Tomlan, who was a sergeant when he was dismissed, allegedly joined the Highwaymen while he was still a police officer and lied to investigators about his membership. He faces additional charges of possession of cocaine and steroids.
Michael Ramsey, a Brownstone police officer, and Dennis Abraham, a former reserve officer in Detroit, were charged with alerting the Highwaymen that a member had become a police informant.
A lawyer, Lee O'Brien, was charged in a criminal complaint with lying to agents about a stolen car he received from a client, Sean Donovan. Donovan, a member of the Highwaymen, faces drug charges, the report said.