Scott Weiland -- Massive Cop Screw Up In Doppelganger Meth Arrest

Scott Weiland is the victim of a series of screw-ups as well as incredible deception. Cops now tell TMZ they were WRONG -- the guy who's been in custody for meth possession and burglary for A MONTH is NOT who they thought it was -- Scott Weiland.

TMZ posted a story late Thursday that Weiland was currently behind bars after allegedly stealing razors from a Bev Hills drug store in late July. The Bev Hills cops said when they searched him, they found meth.

Apparently the guy said he was Scott, and cops believed him.

BHPD gave us a written statement, titled "Celebrity Arrest," which read, "The suspect, former Stone Temple Pilots band member Scott Weiland (46 years of age), was taken into custody..."

The man has been in L.A. County Jail since July 26, unable to post $95,000 bail.

After we posted the story ... Scott posted a video on Facebook of himself at an L.A. recording studio ... to show he was NOT in jail.

We then called the Sheriff's Dept. back but they were unwavering, telling us they did a "physical check" on the inmate and insisted Scott "was definitely in custody."

Oops. The BHPD got back to us late Thursday night and said they made a BIG mistake ... the inmate is actually a 44-year-old guy named Jason Michael Hurley. They discovered it through belated FBI fingerprint analysis, even though he's been locked up since July 26.