Justin Bieber's BFF Lil Za was arrested for drug possession during this morning's police raid on Bieb's house as the police were investigating JB's egging of a neighbor's house.

Za and another pal, Lil Twist, have been living with Bieber for years, as far as we know. They drive his cars, they wear his clothes, they smoke his ...

UPDATE - During a police press conference, a spokesperson said the drug on Lil Za's COCAINE. The officer said the drugs were in no way related to Bieber other than that they were in a friend's possession who was in the house. The officer said the drugs were in plain view when cops raided the Calabasas home.

It was also confirmed that the egging of the neighbor's house is a FELONY crime and that significant damage was done to the residence.