Justin Bieber had pot, Xanax in system at time of arrest, authorities say

Justin Bieber had marijuana and prescription medication for anxiety in his system at the time of his arrest last week in Miami Beach, Fla., the state attorney's office said on Thursday.

The preliminary report issued by the Miami-Dade Office of the State Attorney did not detail the amount of marijuana and alprazolam, better known as the anti-anxiety medication Xanax, that the 19-year-old singer had in his system. Police have said he failed a field sobriety test after they caught him allegedly drag racing on Jan. 23.

According to CBS Miami's WFOR-TV, the report corroborates statements "allegedly made by Bieber to police after he told police he had smoked marijuana and taken prescription pills."

Bieber, who is Canadian, was charged with driving under influence, resisting arrest without violence and driving on an expired license. He has pleaded not guilty to the charges.

The "Boyfriend" singer, who is under the U.S. legal drinking age of 21, also had a minimal amount of alcohol in his system but had difficulty performing a breathalyzer test for alcohol, police said in an affidavit.

The affidavit was posted by WFOR-TV, and its authenticity was confirmed by Miami Beach police detective Vivian Hernandez.

The singer's representatives declined to comment.

Bieber, whose private life has taken a tumultuous turn in the past year, was also charged on Wednesday with assaulting a limousine driver in Toronto in December.

Meanwhile, a petition to deport the singer has gained momentum at WhiteHouse.gov. 

Despite his legal troubles, things are business as usual this week. A new music video for the song "Confident" surfaced this week; Bieber announced the news via Instagram: 

 Watch the new music video below: