Justin Bieber Had Pot, Pills in His System During DUI Arrest: Toxicology Report

Justin Bieber had been smoking marijuana and taking prescription drugs for anxiety leading up to his recent arrest for DUI in Miami Beach, according to a toxicology report obtained by TMZ.

Urine tests processed by the University of Miami's Miller School of Medicine indicate the pop singer had THC and Alprazolam (the key ingredient in anti-anxiety medication such as Xanax) in his system. Bieber tested negative for cocaine, methamphetamines and Oxycodone, among other substances. See the report here.

The report leaks a day after Bieber pleaded not guilty to charges of DUI, resisting arrest and driving with an expired license. Bieber and singer Khalil Amir Sharieff were arrested Jan. 23 after police stopped them for speeding in a pair of rented sports cars. According to a police report, Bieber cursed out the officer and later admitted to smoking pot and taking pills.

Bieber's arraignment is set for Feb. 14, though he does not have to attend.

Meanwhile, the "Boyfriend" singer turned himself in Wednesday night to Toronto police to face a charge that a member of his entourage assaulted a limo driver in December. His attorney insists Bieber is innocent.