The sources said Bieber, a Canadian citizen, left the plane and was taken to the customs terminal at the airport, which serves private aviation and is packed with planes coming in for the big game.
The plane arrived Friday just before 3 p.m. from Toronto when inspectors with Customs and Border Protection thought they smelled marijuana and began a search, the sources said. Trained drug-sniffing dogs helped search the plane, and Bieber was interviewed at length before agents decided to admit him hours later.
This comes after a string of recent run-ins with the law. Just days ago, the pop singer turned himself in to Toronto police in connection with an alleged assault on a limo driver that happened last year.
According to Toronto police, Bieber went to a hockey game on Dec. 29 at the Air Canada Centre, then later that night police were called to the area and began investigating whether it was the singer or a member of his entourage who was involved in the assault. Bieber was charged with assault in the case and released.
Bieber, 19, was also arrested for alleged DUI and drag racing in Miami, after leaving a nightclub around 4 a.m. Jan. 23.
Before that, Bieber's Los Angeles home was searched in early January, as police for looking for evidence he was involved in a neighborhood egging that could result in a felony.
Attempts to reach Bieber's rep have not been returned.