JUSTIN BIEBER returned from his trip to Asia yesterday.  But when he landed at Los Angeles International Airport, Customs agents wanted to have a little talk with him.  A FOUR-HOUR talk.


It's not clear what went down.  One website called it, quote, "routine secondary questioning."


By the time Justin was finally released, the paparazzi were waiting

This has happened to Justin before.  When he flew from Canada to New Jersey for the Super Bowl earlier this year, they actually detained him while they searched his plane for DRUGS.