The theft was reported on Saturday evening.
According to Atlantic City Police, the victims returned to their hotel room at Resorts Casino around 6:30 p.m.
As they went into the room, police say, one of the suspects emerged from the closet and ran away.
Police say the man got away with prescription medication.
Investigators have also said that suspect was seen with two other men on surveillance video.
Anyone who can identify the suspects is asked to call the Atlantic City Police Department Criminal Investigations Unit at 609-347-5766.