MIAMI >> A preliminary toxicology report shows that Justin Bieber tested positive for marijuana and the anti-anxiety drug Xanax after his arrest last week in South Florida.

The report released today also shows no presence of other illicit drugs in Bieber’s system, such as cocaine or oxycodone. The 19-year-old pop star was arrested last week on Miami Beach on charges of DUI, resisting arrest and having an expired driver’s license.

Bieber has pleaded not guilty but told police after his arrest last week that he had been smoking marijuana and took a prescription drug.

A previous police report found that breath tests placed Bieber’s blood-alcohol content below the .02 level considered intoxicated for under-21 drivers. Bieber was stopped after police suspected he and another driver were drag racing exotic sports cars.