Police have raided the headquarters of an outlaw motorcycle gang in Bunbury searching for evidence over a violent brawl between Coffin Cheaters and Finks at the Kwinana Motorplex early this month.
About 20 police carried out two simultaneous raids at the Coffin Cheaters headquarters in Zoe Street in central Bunbury and a house in Eaton at about 9.40am.
A man is being questioned by police.
Today's raids are the latest in a series of police operations as they search for a gun said to be used in the brawl.
Three members of the Finks gang required surgery after suffering serious injuries in the fight.
One man suffered a gunshot wound to his leg while another had three fingers severed with a knife.
The clash was between members of the rival Finks and Coffin Cheaters gangs but police have confirmed that Club Deroes bikies were also involved.
Police have also searched the Finks' clubhouse at Balga in Perth's north, other city properties and premises in Mandurah and Geraldton.