Justin Bieber has been branded 'Justin Thiefer' by British rapper Lethal Bizzle after the troubled pop star adopted his name on Instagram.
Bieber has baffled fans by changing the name on his official Instagram page to 'Bizzle' and the move has outraged the hip-hop star.
Lethal Bizzle has sent a message to Bieber via Twitter, writing, "Oi Justin Bieber I hear your catting my name? Leave it yeah."
He also posted a picture of a news article about Bieber's name change next to his own disgruntled face with the caption, "Leeeeeave it yeah (sic)."
The star adds in a statement to British newspaper The Sun, "Myself and the Dench Gang (fans) ain't happy about it. Nothing cool about the cheesiest boy in pop using your name to be 'cool'. He needs to Leave it yeah! Justin Thiefer."
Meantime Bieber has reportedly been caught on camera urinating in his Miami jail cell.
The 19-year-old was arrested in the Florida city on January 23 for DUI, driving with an invalid license and resisting arrest after he was allegedly caught drag racing on a residential street.
According to celebrity news website TMZ.com, Bieber has asked to obtain all police video related to the incident after a clip of the star getting a pat down surfaced last week.
TMZ reports footage of Bieber relieving himself in his cell is causing the most concern.
Bieber's lawyers claim the video shows their client "in various states of undress, which show intimate personal parts" of his body, according to TMZ.
Earlier this year, Bieber was accused of causing $US20,000 ($A22,415) of damage to the property by pelting the food, which could result in a felony vandalism charge for the singer.
He is also facing problems in Canada, where he handed himself in to police on January 29 following claims he assaulted a limousine driver.
