The constable who spilled the beans on the alleged criminal organisation led by former police inspector David Gatt had been fined over his part in a Paceville fight in which he disobeyed the orders of colleagues on duty.

News of the case, which was decided by a court of appeal in 2008, emerged during a hearing of the case against Romeo Bone, accused of stalking PC Mario Portelli.

Defence lawyer Gianella Caruana Curran asked prosecuting officer Michael Mallia whether it was true the officer had a conviction for a violent crime.

Police Inspector Mallia confirmed PC Portelli had been charged, adding he had been acquitted.

However, records of the case traced by The Times show the officer was not acquitted of all charges. PC Portelli, together with another two officers, PC Mark Anthony Buttigieg and PC Sandro Mamo, had been cleared of assaulting four policemen and slightly injuring a man during a fight with bouncers outside the Paceville club Fuego in 2002. When members of the police mobile squad intervened the three off-duty constables also argued with them.

The Magistrates’ Court had found them guilty of making threats, fighting, breaching the peace, disobeying police orders and committing a crime they were in duty bound to prevent. They were fined just over €400.

PC Portelli is the main witness of the prosecution in the case against Dr Gatt (he graduated as lawyer after being dismissed from the police) who stands charged with being the mastermind behind major hold-ups, including the failed heist on the HSBC headquarters in June.

PC Portelli testified he had been friends with Dr Gatt for the past six years, during which the former officer would tell him about various crimes he allegedly directed.

PC Portelli said he decided to spill the beans when Dr Gatt started telling him about crimes he planned, including an alleged assassination plan on former Prime Minister Eddie Fenech Adami.