Police have searched the home of Justin Bieber for evidence after the Canadian pop star allegedly threw eggs at his neighbour's home.
Officials did not say what evidence they took from the home, but arrested a member of the singer's entourage for alleged cocaine possession.
The egging apparently caused serious damage to the neighbour's home in the Los Angeles suburb of Calabasas.
Police said Bieber, 19, had "not been arrested, nor has he been exonerated".
Bieber co-operated with detectives but was not interviewed, Lt David Thompson told reporters, adding a judge had signed off on a search warrant.
"I get that the eggs don't seem that significant, but it does rise to the level of a felony," he said.
"There is a victim in this case who has extensive damage done to their home. And that's a serious incident."
Officials were not disclosing the name of the Bieber associate arrested,
The LA County Sheriff's Office say they were looking for surveillance video tapes when they spotted the drugs "in plain view".
Speaking to the BBC's Newsbeat programme, Steve Whitmore from LA County Sheriff's Office said: "There were about eight people at the residence, they were detained.
"Justin Bieber was there as well. He was also detained, not arrested.
"The alleged narcotics were in such a location that they were directly related to one person and not related to the house at large."
He said "it is possible" that the drug was cocaine but tests would be carried out.
Two previous investigations into Bieber's conduct by the sheriff's department have not led to charges.
Prosecutors declined to charge last year him after a neighbour complained he drove recklessly through the area, and in November 2012 after a paparazzi photographer accused Bieber of assault.