West Australia's corruption watchdog has asked WA Police to investigate the conduct of officers involved in a clash which left one man in hospital and a policeman partially paralysed.

The Corruption and Crime Commission has requested police investigate an incident in 2008 outside the Old Bailey Tavern, in Perth's north, which left Constable Matthew Butcher partially paralysed and brain damaged.

Const Butcher was one of three officers who tried to calm down a fight between patrons who had been drinking at the pub in Joondalup.

Robert McLeod and his sons, Barry and Scott, were acquitted in 2009 of assaulting the policemen.

In January, Const Butcher was given a $3.3 million ex-gratia payment, believed to be the largest given to an officer injured on duty anywhere in Australia.