Paramus Catholic High School vice president of operations Artur Sopel and teacher Michael Sumulikoski are charged with sexual assault, child endangerment and hindering apprehension.
They were arrested on Tuesday after a month-long investigation.
Sumulikoski is accused of have sex with one female student on the trip, which took place from Feb. 17 to Feb. 27.
Sopel is accused of engaging in sexual activities with two female students in Germany and having sex with another female student during the 2010 school year.
Sopel is held in the Bergen County Jail on $225,000 bail. Sumulikoski is held on $50,000 bail.
It's not clear whether either man has retained a lawyer.
