A cop enjoying his Starbucks Frappuccino says he got a nasty surprise halfway through, when he discovered a tampon floating around in his drink … and there’s now an official police investigation.

An off-duty LAPD officer purchased his Frapp Friday at a Starbucks inside a Target in Diamond Bar, CA. He used his police credit union debit card to buy the drink, and says he found the feminine hygiene product inside … before marching back into the store to confront the staff.

We’ve confirmed the L.A. County Sheriff’s Department took a report and is now investigating it as a possible food tampering incident. Deputies are pulling surveillance footage.

The L.A. Police Protective League is calling the incident a “disgusting assault on a police officer” and says it was “carried out by someone with hatred in their heart and who lacks human decency.” They want whoever may be responsible exposed and fired. Fox 11 L.A. was the first to report this story.