Authorities in Canada have accused a Justin Bieber impersonator of threatening and sexually abusing a 12-year-old girl in New Jersey on a video chat site.

Acting Essex County Prosecutor Carolyn Murray says 34-year-old Lee Moir of Toronto, Ontario, posed as the pop star on Facebook. Authorities allege he threatened to harm the girl's family to force her to perform sex acts online.

It's unclear if Moir used photos of Bieber on his Facebook page, but authorities say the girl realised it wasn't the pop star during the video chat.

He was arrested after an undercover Canadian officer posed as a 14-year-old girl online. Authorities say Moir engaged the officer in sexual conversations and requested a meeting and was arrested.