Loading But Mr Ashton said on Thursday police were, at the time, under intense pressure to stop the bloodshed. "Every court that has looked at this matter has obviously used colourful adjectives to criticise us and they all seem to want to take it to the next level in terms of coming up with those adjectives," he told The Age. "Everyone has criticised us ... Everyone I've talked to with a law degree has had a similar outrage: How could a lawyer do this? How terrible are the police that they were involved in this? "[But] it's a different role when you're in the police and you're trying to deal with community safety. If you think about the time back then ... [there] were very serious public safety issues they were trying to balance up."

He said the benefit of hindsight will determine whether the ends justified the means. "When this matter eventually finishes, with a royal commission and court cases, people will look back and they'll say, with the benefit of hindsight, whether the ends justified the means," he said. "When you're trying to manage that sort of risk and police at the time would've been trying to do that, they don't know what those ends look like at that time." Mr Ashton was at the Office of Police Integrity, which was replaced by the Independent Broad-based Anti-corruption Commission in 2013, when Informer 3838 was used.

He was on two steering committees that had oversight of two investigations that involved police corruption where Informer 3838 was used or were they tried to use her. Mr Ashton said he was bound by the OPI's secrecy provisions and he could not talk about investigations he conducted in his official duties at the OPI without authorisation. "But I will be able to tell the royal commission," he said. "I'm confident my actions in that I didn't do anything wrong and I'd like to be able to talk about it and I will be able to talk about it if the royal commission invites me to." Mr Ashton left the OPI and joined Victoria Police in 2009. In 2011, he said he instigated an internal review into the use of Informer 3838.

By then, the lawyer – who has also been dubbed Lawyer X – had been deregistered as an informer so she could become a key witness against suspected corrupt police officer Paul Dale in a court case in 2010. Mr Dale, who denies involvement, was being investigated over the 2004 murders of police informer Terence Hodson and his wife Christine. Former drug squad detective Paul Dale at Melbourne Magistrates Court in 2010 for proceedings over the murder of police informer Terence Hodson. Credit:Craig Abraham The case collapsed after serial murderer and drug dealer Carl Williams was killed in prison in April 2010 after he too became a witness against Mr Dale. Soon after, Informer 3838 sued Victoria Police, claiming they breached their duty of care while she was a protected witness.

Loading Mr Ashton said the internal review of her use was kicked off primarily because of the risk to her safety in a second case against Mr Dale. Mr Dale was accused of lying to the Australian Crime Commission, but he was acquitted in 2013. "What I was hearing in those briefings was enough to give me concern that we needed to make sure everything was OK," Mr Ashton said. When asked why he didn't initiate a similar review if he had those same concerns about her safety when he was at the OPI, Mr Ashton said his role was very different at the integrity body than the role he would go on to have in the force. "I was in the area doing police oversight of, and the extent police corruption was involved in, investigations," he said.

Murray Kellam QC at IBAC conducted another investigation into the matter, stopping short of a criminal finding, but said the informer's use had the potential to adversely affect the administration of justice. "I don't believe anything illegal was done, certainly not by me, but I think overall I don't think anything illegal was done," Mr Ashton said. "I drew some comfort from the Kellam review." The High Court decision was a result of an appeal by Mr Ashton and the force. Victoria Police launched legal action against the Office of Public Prosecutions in 2016 to stop them notifying former clients of Informer 3838 that the lawyer was an informer at the time she acted for them. They argued the information would result in the murder of the lawyer, something that should outweigh other considerations.