Justin Bieber is reportedly ''smoking more weed than ever'' since moving to Atlanta.

The 'Boyfriend' hitmaker is said to have sparked concern among his friends since moving out of Los Angeles - where he had a schedule set up by people connected to his business affairs - as he no longer has any real rules or plans, with insiders claiming he spends much of his time smoking marijuana or consuming sizzurp, a cocktail of Sprite, Jolly Tancher sweets and medications codeine and promethazine which is referred to by the singer and his pals as 'lean'.

A source told TMZ: ''He is constantly high. Drinking more lean, smoking more weed than ever.''

The insiders claim Justin doesn't really leave his house, but is spending a lot of time working on hip hop music in his recording studio - and is ''rarely sober''.

The 19-year-old singer - who has caused controversy with his recent antics, including being arrested for allegedly assaulting a limo driver, and also for driving under the influence (DUI), driving with a suspended license and resisting arrest - is said to be cutting down his inner circle, pushing away those who have ''confronted'' him about his drug use, and those who have ''ratted him out'' about his habits.