Justin Bieber Goes Off on Another Pap -- I'm Taking Your Memory Card Bitch!!!

Justin Bieber was the ringleader in a SECOND pap altercation in Miami Wednesday -- ordering his goons to steal a photog's camera ... all while the man pled desperately for mercy -- and the entire exchange was caught on tape.

The incident occurred outside The Hit Factory recording studio at around 4 AM ... just hours before Bieber's security guards allegedly choked another photographer, and tried to jack his camera equipment as well.

On the tape, you hear Justin scream to his bodyguards, "Grab that camera!!! Get that f***ing camera out of here!!!" (time code: 1:08)

You can hear the photog plead with Justin, who responds like a benevolent prince, "Alright, alright. I'm gonna give you your camera back. I'm gonna take your SIM card though."

The photog begs and pleads to let him keep his memory card -- even offering to delete the photos he took -- but Bieber is unmoved.

Authorities are currently investigating the altercation that took place later in the day -- but law enforcement tells us, police have no record of the earlier incident because it wasn't reported.

We reached out to Justin's people ... so far, no comment.

All told, Bieber's had three run-ins with photogs while in Miami this week -- the first incident occurred Monday night at the American Airlines Arena following the Heat game. Someone snapped this pic of Bieber on his cell phone and the singer reportedly flipped out.