Roughly a dozen investigators searched Bieber's home and arrested one member of the singer's entourage on suspicion of drug possession, Lt. David Thompson said.
The man was later identified as Lil Za, a rapper whose real name is Xavier Smith. Jail records show Smith, 20, was being held in lieu of $20,000 bail. Thompson said the drugs linked to Smith were in plain sight when detectives searched Bieber's house.
The drug was initially described as cocaine, but authorities later said they were testing it to verify its contents.
Bieber, 19, was at the home and cooperated with authorities but was not interviewed by detectives. Thompson said he expected the singer to speak with detectives when his attorney could be present.
"He has not been arrested, nor has he been exonerated," Thompson said of Bieber.
Thompson declined to describe what evidence detectives took from Bieber's home, but said the emphasis wasn't on what was in the pop star's refrigerator.
He said the house Bieber allegedly egged had custom wood and other expensive features and that several thousands of dollars in damage occurred. Thompson added that a judge authorized the search warrant.
"I get that the eggs don't seem that significant, but it does rise to the level of a felony," Thompson said. "There is a victim in this case who has extensive damage done to their home. And that's a serious incident."
The singer lives in a gated community in Calabasas, a celebrity enclave about 30 miles northwest of downtown Los Angeles. Four helicopters hovered over the neighborhood hours after the warrant was served.
An email message sent to Bieber's publicist, Melissa Victor, was not immediately returned.
Previous investigations into Bieber's conduct by the sheriff's department have not resulted in charges.
In October, prosecutors declined to charge Bieber after a neighbor complained he drove recklessly through the area. Prosecutors in November 2012 also declined to charge the singer after a paparazzo accused him of punching and hitting him after leaving a Calabasas movie theater.
Neighbors have complained about Bieber and his friends' behavior, but Thompson said the warrant wasn't served to send a message to the singer, but that might be one result of the search.
"We didn't do this search warrant to send a message, that's not what we do," Thompson said. "But we hope maybe understanding the gravity of this will change some of the behavior."