On any ordinary occasion scrapping with a cop would result in cuffs, a paddy wagon, a cell and probably worse. Yet, that is exactly what Australian Jake Andrewartha has been doing before his Olympic debut at London's ExCel arena this week.

Surrounded by armoured trucks, water cannon and automatic weapons, he sharpened up for the fight of his life in Fukuoka, Japan, measuring himself against the hardened, professional martial arts warriors that are the city's riot police.

Australian judoka have special access to the facility, with an open invitation extended because of a long-standing relationship between the Olympic team head coach, Stewart Brain, and the judoka of the riot police squad. Judo has been practised by Japanese police for more than a century and when the special unit in Fukuoka is not called into action on the streets - ''there's not too many riots in Japan, I'll give you the tip'', Brain says - they are found on the mat twice a day, training and competing in the country's formidable police league.