Police have revealed a property damaged in a suspicious fire in Sydney's west on Sunday night is linked to a motorcycle gang. Emergency services were called to the industrial unit at Mount Druitt about 11:00pm AEST. Police say the blaze caused extensive damage to the ground floor and second-storey office areas. Chief Inspector Bill Pearce says the gangs squad has been called in. "We believe that the premises are owned or leased or rented by persons who are associated with a motorcycle group and as a result of that we're following certain lines of inquiry in relation to the fire which we believe is certainly suspicious," he said.