Steven Hadley, 31, of Port Republic, has been charged with four counts of second-degree official misconduct.
In a news release, the Atlantic County Prosecutor's Office said "Hadley committed unauthorized exercises of his official function as a police officer in order to obtain benefit for himself, specifically sexual contact."
Investigators say Hadley was on the job when he participated in sex acts with four women on various occasions from January 2010 through May 2013.
Just yesterday, the same day the charges were filed, Hadley was involved in a serious single car crash on the Garden State Parkway. His pickup went off the road into a tree and caught fire.
He is now in the burn unit at Temple University Hospital in critical condition.
His attorney says the car crash is not connected to the criminal charges, but a terrible coincidence.
In a written statement Hadley's attorney, Joseph A. Levin, said: "For years, Officer Hadley has served his community with honor and distinction. Other than his loving family, there was and is nothing more important to him than his honorably serving as a law enforcement officer. Officer Hadley is saddened by these allegations but they are just that, allegations. He respectfully requests that no one rush to judgment while he pursues a vigorous defense and a just resolution."
Officer Hadley has been suspended without pay from the department while this investigation is under way, according to his attorney.
If convicted, Hadley faces 5 to 10 years in prison and up to $150,000 in fines.