Nicola Gobbo, 47, one of the country’s top defence lawyers, is the subject of a public inquiry that could see murderers and others freed.

Ms Gobbo, who is the niece of Sir James Gobbo, a former governor of Victoria and Supreme Court judge, gave police more than 1,000 intelligence reports on her clients and their associates.

Her evidence she believes helped bring charges against more than 350 people and topple a massive drug trafficking operation in Melbourne run by the Mokbel family, whose paterfamilias, Tony Mokbel, was one of her clients.

The inquiry heard their relationship was more than the “normal lawyer-client relationship”.

Mr Mokbel was extradited to Greece where he is serving a 30-year sentence for drug trafficking.

Prosecutors have told at least 22 convicted criminals that they could have grounds to appeal.

“Any conviction in any case where Gobbo played anything but a very minimal role in providing legal services is almost certainly going to be overturned,” Jeremy Gans, a law professor at Melbourne University, said.

A police task force is also looking into Ms Gobbo’s relationships with some officers, the inquiry heard. 

Neil Paterson, Victoria’s assistant police commissioner, told the commission: “There has been talk of inappropriate relationships, perhaps intimate relationships, with police members.”

Ms Gobbo is in hiding.