Justin Bieber was held for four hours by customs officials after touching down in LA on Thursday.
The 20-year-old singer was arriving back in the US from Tokyo with his entourage, but was temporarily detained at LAX for "routine secondary questioning".
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"It's standard, especially after he has had other legal issues in the US in the past," a source told US Weekly.
This year, the Canadian pop star has had a number of run-ins with the law, including a DUI arrest and assault charges.
He also raised a few eyebrows during his time in Japan, when he made a visit to the Yasukuni Shrine war memorial, which honours Japanese war dead, including 14 convicted war criminals from World War II.
His recent behaviour has prompted a petition to revoke his green card — but on Monday, the White House said they would not be commenting on the document, which has 274,000 signatures.
"Sorry to disappoint, but we won't be commenting on this one," read a statement. "We'll leave it to others to comment on Mr. Bieber's case, but we're glad you care about immigration issues…"