A Newark man has been charged with sexually assaulting a young boy over at least a three-year period.

The suspect, 34-year-old Jose Reyes, had been employed at a Short Hills health club where he watched children while their parents worked out. Investigators fear there may be more victims.

The Essex County Prosecutor's Office says the assaults may have gone on for up to four years and occurred at the boy's home in Bloomfield. The victim, now 17, went with his mother to Bloomfield police to report the alleged abuse. Reyes is reportedly a longtime friend of the victim's family.

Reyes is charged with four counts of first-degree aggravated sexual assault and three counts of child endangerment.