Monmouth County prosecutors said Friday that 45-year-old Officer Keith German is accused of advising reputed gang members, tipping them off to police investigative techniques and providing other assistance.
He is free on bond on charges of official misconduct and unauthorized access of a computer database.
The patrolman's attorney tells the Asbury Park Press he will plead not guilty. The officer lives in Tinton Falls and has been on the police force for 16 years.
No motive for his alleged assistance was cited.
Thirty-one people, including the officer, were charged in the investigation, which targeted the Crips and Bloods street gangs.
The defendants were arrested on charges ranging from racketeering conspiracy and promoting organized street crime to robbery, drug trafficking and shoplifting.