No, we're not talking about the FAKE Jepsen pics floating around the Internet ... sources tell us the photos in question are the real deal and have not seen the light of day ... and the Canadian-born singer is desperately trying to keep it that way.

Law enforcement sources tell TMZ ... Jepsen's camp received an anonymous tip about the pics back in March ... and immediately called the Vancouver Police Department to report the cyber crime.

Cops jumped on the case ... and confirmed the tip was legit, Jepsen HAD been hacked.

A rep for the Vancouver PD tells us an active investigation is underway "in regards to a theft of electronic property belonging to Jepsen."

In fact, we're told cops already have a potential suspect lined up.