Justin Bieber's pet monkey Mally has been seized and placed in quarantine after customs realised the singer didn't have the correct paperwork to bring him into Germany.The 19-year-old singer sneaked Mally into Europe on a private jet before it emerged he didn't have papers for the animal, and he now faces prosecution in Berlin after breaking strict health laws.A source told The Sun newspaper: "Justin has been acting like a right diva. He is out of control and lives in an alternative reality to the rest of us."He didn't think about the potential risks of flying a monkey from one continent to another. He and Mally go everywhere together. He will be heartbroken it has been put in quarantine."He seems as fond of Mally as Michael Jackson was of his chimp Bubbles."It is said the 'Beauty and the Beat' hitmaker was detained for some time and could face a fine of over £10,000.A customs spokesman added: "The animal required a certificate of health and other authorisations."You cannot just land with a wild animal and bring it into the country if the flight has not originated from another EU country and you don't have the proper paperwork."