Justin Bieber
Justin BieberCreative Commons/ Fernanda.fer

Justin Bieber was detained at the Los Angeles International Airport, or LAX, soon after he touched down from his Japan trip on Thursday afternoon.

Reports have it that Bieber was questioned at the airport's Tom Bradley International Terminal by U.S. Customs officials for nearly four hours. The Canadian pop star appeared in good spirits after being released and he stuck out his tongue and smiled while being greeted by a throng of media personals.

Bieber went through a routine secondary questioning because of his recent run-in with the law, and not due to any new charges, reports said. Bieber was first arrested in January for driving under the influence and since then he has had several run-ins with the law, including vandalism and assault charges.

"The 2001 Patriot Act, signed by former President George Bush and extended by current President Barack Obama, gives custom officials the broad authority to flag travelers arriving from a foreign country when they have an active criminal case or a conviction," LA attorney Mychal Wilson told HollywoodLife. "Presumably, Justin Bieber is on the Homeland Security watch list due to the various pending criminal charges against him."

This comes just a week after the White House rejected a petition seeking to deport Bieber from the American soil as he "is a terrible influence on our nation's youth."

The petition had amassed more than 273,000 signatures.

This is not the first time Bieber has been detained at an airport. The 20-year-old and his father were accused of abusing a female flight attendant in January and the flight was briefly detained when it landed in Teterboro, N.J.

"The captain of the flight stated that he warned the passengers, including Bieber, on several occasions to stop smoking marijuana," the official report of the incident stated, according to NBC. "The captain also stated he needed to request that the passengers stop their harassing behavior toward the flight attendant and after several warnings asked the flight attendant to stay with him near the cockpit to avoid any further abuse."