Three security guards have been removed from Leavers celebrations in WA's South West with one charged over an alleged assault on a police officer.
Police at the Leavers' entertainment zone in Quindalup overnight removed two guards after they were seen "behaving in an erratic manner".
Officers then questioned a third security guard who is alleged to have become aggressive before trying to run from the police.
He was restrained after a struggle, during which he allegedly bit a male senior constable on the hand causing his skin to break.
The guard was searched and an amount of what is believed to be methamphetamine was found on him. This item will require further testing.
A 22-year-old Secret Harbour man has since been charged with assaulting a public officer and will appear before the Busselton Magistrates Court on December 14.
Inquiries will continue into the matter.