Police charged two Rebels outlaw motorcycle gang associates and seized drugs and weapons near Colyton on Tuesday.
At about 11.20am, officers from Strike Force Raptor, established to investigate outlaw motorcycle gangs, observed men they believed to be acting suspiciously near parkland off the Great Western Highway, Colyton.
Police tried to stop one man as he was driving from the scene, but he ignored them and drove away.
Police said during the pursuit the man threw a number of items out of the vehicle.
They eventually stopped and arrested him in Roper Road.
Police also recovered some of the items he discarded.
They allegedly included a replica firearm and small quantities of methamphetamine and cannabis.
The man, a 25-year-old Rebels associate from Cecil Hills, was taken to Mount Druitt police station and charged with possessing a prohibited weapon and possessing prohibited drugs.
He appears in Mount Druitt Local Court on July 17.
Police also arrested and charged another man in connection with the incident.
The man, a 37-year-old Rebels associate from Croydon Park, was charged with larceny, possessing a prohibited drug and goods in custody.
He also appears in Mount Druitt Local Court on July 17.
Strike Force Raptor investigators urged anyone with information about outlaw motorcycle gangs to contact them through Crime Stoppers on 1800 333 000.