P OLICE IN THE state of Victoria spent millions of dollars trying to keep their arrangement with Informer 3838 a secret. She was a young criminal barrister who snitched on some of Australia’s most notorious drug lords while she was representing them in the 1990s and 2000s. The informant, whose name is protected by the courts, claims her actions helped convict nearly 400 criminals. She also violated their right to confidentiality and possibly, their chances of a fair trial. Dozens of gangsters could walk free now the affair has become public.

The police claimed the lawyer would be murdered if her clients discovered she had double-crossed them. But the High Court lifted suppression orders on the case in December, saying that faith in the courts was more important than her personal safety. Informer 3838 had committed “fundamental and appalling breaches” of her duties as a barrister, it ruled. Police had “corrupted” prosecutions and “debased fundamental principles of the criminal justice system”. A royal commission is investigating.

Before that inquiry began in February the police admitted that the lawyer had been dishing dirt for a decade longer than they previously thought: from 1995 to 2009. Neither was she alone. Six other legal clerks, secretaries and solicitors were on police books, some as recently as 2016. Other states are asking whether their forces resorted to similar tactics. More than 20 prisoners were told last year that they might have grounds to appeal against convictions secured using ill-gotten information. Three are already doing so. If other professionals snitched on their clients, it follows that more sentences could be in jeopardy.

Melbourne was shaken by the gang wars that raged between 1998 and 2010. At least 36 mobsters were killed in that period, and police were desperate to punish the perpetrators. But citizens’ right to confidentiality when speaking to their lawyers is enshrined in law. “Police shouldn’t ask and lawyers shouldn’t tell,” says Arthur Moses, president of the Law Council of Australia. Officers knew that well. Ron Iddles, a former detective, reckons that up to 15 senior policemen turned a blind eye to the arrangement with Informer 3838. “They saw the risks,” he said in a television interview, “but there was directions from above.”

This is not the only controversy to cast a shadow over Victoria Police. This year officers in the state have been accused of falsifying a witness statement and of battering innocents. One victim was a meekly compliant pensioner arrested for drunk driving who was knocked out by an angry copper (he kept his job). Another was an aboriginal teenager who was arrested despite not remotely fitting the description of the criminal the police were hunting, and allegedly assaulted. Complaining about brutality seems futile, though. Most misconduct allegations are referred to the police themselves for investigation. In cases of assault, less than 4% are ever proven.