Pop star Justin Bieber was detained and questioned upon arrival at Los Angeles International Airport, a source familiar with the investigation told NBC News late Thursday.
The singer, 20, was reportedly headed back to the U.S. following a trip to Japan when he was stopped.
Customs and Border Patrol spokesman Jaime Ruiz told NBC News he could not comment on the matter because of federal privacy laws.
Bieber's representative declined to comment on the matter.
Whether Bieber's detention was related to his recent legal woes remains unclear. Bieber has pending legal cases in Los Angeles County and Miami. The singer is also facing an investigation by the Federal Aviation Administration over claims he interfered with a member of the flight crew while traveling between Canada and New Jersey.
An online petition signed by nearly 300,000 people called on the U.S. government to deport Bieber back to his native Canada. The petition stated that the people of the U.S. feel "we are being wrongly represented in the world of pop culture. We would like to see the dangerous, reckless, destructive, and drug abusing, Justin Bieber deported and his green card revoked."
Last week, a response of "no comment" regarding the petition was issued from the White House through the "We the People" program.
In recent days the "Baby" singer came under heavy ctriticism during his trip to Japan after he publicized a visit to the Yasukuni Shrine on Instagram.
2.5 million war dead are enshrined at Yasukuni, including Japan's 14 convicted war criminals. Also at the site is a war museum that defends Japan's wartime aggression. China and South Korea see Yasukuni as a symbol of Japan's past militarism.
Bieber apologized for the visit via Instagram, stating that he "was mislead (sic) to think the Shrines were only a place of prayer. To anyone I have offended I am extremely sorry."