Police say a man has been arrested for impersonating an FBI agent and unlawfully imprisoning a woman.  

According to police, Brandon Knapp claimed to be an FBI agent and made contact with a 28-year-old woman after she posted on a social media website.

The victim then invited him to meet her at a relative’s residence in Commack, where Knapp convinced her he could take her to a safe house.

When he and the victim left in a 2004 Mercedes Benz, a concerned family member called her cellphone.

After speaking with the victim, the family member feared for the victim’s safety and called police, who were able to locate the vicinity of the victim’s phone.

Police were dispatched to the area, and the victim was dropped off at a nearby restaurant.

Police responded to the location and transported her to the Seventh Precinct.

Knapp was identified and located in Riverhead, and he surrendered.

Knapp, 27, of Center Moriches, was charged with criminal impersonation and unlawful imprisonment.

His attorney said that Knapp denies the allegations against him.

Detectives are asking anyone who believes they might have been a victim of Knapp’s to contact the Fourth Squad detectives at 631-854-8451.