Mr Gerondis, who headed a 2009 investigation into a woman who stole more than $40 million from ING, was instrumental in helping police catch Newcastle fraudster Lemuel Page.

As the head of Fraud Risk Management Services, Mr Gerondis was contracted by one of Page’s victims, a Sydney orthodontist who lost millions in his dealings with the fraudster.

He provided advice to the victim and helped build a case that ended with Page being sentenced to eight months’ jail.

“Blokes like Page are very good at what they do,” Mr Gerondis said. “They rarely leave a paper trail, they have perfected the art and know exactly what they are doing.”

He urged anyone who was a victim of Page to speak publicly and said they should not feel embarrassed or foolish.

“To get tricked by someone like him, it’s not something you should be ashamed of,” he said. “The more that is out there in the public about what has happened, the better it is for everyone. If people speak out it’s going to save potential victims a lot of anguish. It dries up his victim pool.”

Red flags include confidential deals that need to be settled quickly.

“Don’t get involved in something you don’t know anything about,” he said. “Make sure you have got the right paperwork and if you are told the deal is secret and needs to be done in a hurry, you’ve got a  problem.”