The Situation -- Cops SWARM Ferrari ... For Autographs

The Chief of Police in Belmar, NJ says he plans to investigate a curious Ferrari encounter between The Situation and The Boys in Blue ... after TMZ obtained footage which appears to show starstruck cops turning a blind eye to some obvious law-breaking.

The video -- shot Sunday night -- shows three uniformed officers laughing and joking with the "Jersey Shore" star after he stopped to ask for directions. According to sources at the scene, Sitch was even signing autographs for the cops.

Here's the problem -- during the encounter, two girls are crammed in the Ferrari's single passenger seat and neither one is wearing a seat belt ... a clear violation of NJ law.

But the cops didn't seem to care. In fact, they sent Sitch and the girls on their way WITHOUT A TICKET while the ladies were still illegally piled up in the passenger seat.