Can Justin Bieber's recent destructive behaviour be finally explained?

The 19 year-old might be described as arrogant, rude or just a spoilt brat, but not once has he been suspected of drug use, until now.

Even when Bieber's house was raided, and his good friend Lil Za was arrested for possessing the ecstasy drug MDMA, the 'Love Me' singer came up clean.

However, a new report from TMZ claims that Justin's close team are urging the singer to check into rehab after concerns have grown over him becoming addicted to codeine.

Sources close to Bieber have told the gossip site that he and his friends regularly drink lots of 'sizzup', an addictive beverage which contains a powerful cough syrup mixed with a soda drink, and he only gets the top of the range product.

The report states the 'Believe' hit maker and his pals refer to the concoction as "lean".

The side-effects can be devastating with regular users suffering from seizures, and in some cases, something worse.

The 'Never Say Never' singer is an alleged fan of 'Actavis Prometh', a prescription-strength cough syrup that contains codeine, and costs around $800 for a full pint.

The only way to purchase the medication is with an official prescription or from locations outside of the US (most likely illegal).

The gossip site was apparently told that Bieber is supplied from a connection outside of the US.

This isn't the only narcotic Justin is taking either, TMZ also reports he is a frequent weed smoker, drinks lots of alcohol (even though he is still under age) and takes the prescription pill Xanax.

Bieber's team are desperately trying to convince him to check into rehab but so far he has refused.

Justin Bieber
Bieber is apparently taking several different drugs