EXCLUSIVE

Toby Sheldon -- who became famous for spending more than $100k to look like Justin Bieber -- has been found dead ... TMZ has learned.

We're told Toby's body was found in a Motel 6 in the San Fernando Valley on August 21. He has been reported missing since August 18.

Law enforcement tells TMZ, police found drugs in the room but it's unclear how he died.

When Toby went missing, the LAPD said the disappearance may have been triggered by a breakup with his boyfriend.