An inquiry into police use of informers in Melbourne has been told toward the end of her third stint as a Victoria Police informer, the once high profile gangland barrister was suffering a barrage of physical and mental illnesses.

Her life went from nights out drinking with police and partying with the underworld to just a handful of people - a solitary friend, her sister and her police handlers.

"I've got the distinct feeling towards the end she had no-one else to talk to about anything," a handler, known as Officer Green, told the inquiry.

She would tell Mr Green and his colleagues that "I must be crazy doing this" when talking about her informing, and that she needed help.

They recommended a psychiatrist, but she refused, telling them that talking to the handlers helped.

"I think she had one friend she regularly visited from time to time, but other than her sister, she was quite lonely," he said on Tuesday.

She came to see one of her handlers, Mr White as a father figure. Her own father died when she was a teen.

Ms Gobbo was "striving for 100 per cent level of trust by Mr White", the inquiry heard.

That wasn't necessarily surprising from the women who told officers as early as 2007 that she wanted to be the best source.

Mr Green said officers tried to be narrow in the tasks they set Ms Gobbo as an informer, but the information coming back from her was "voluminous".

"In my mind, the danger of her trying to be the best source means she starts going out looking at other things outside of the tasking we'd given her; even more so than that we were already having to contend with," he said.

Ms Gobbo's barrister Peter Collinson questioned whether Ms Gobbo seemed psychologically dependent on handlers and acted like she wanted to be a member of their team.

"Yeah, you could sort of say that," Mr Green said.

She told handlers she was looking for new jobs, mentioning analyst-type roles.

The inquiry has previously heard handlers had suggested she become a "talent scout" for the unit while she asked about participating in the US Federal bureau of Investigation's criminal profiling course.

Australian Associated Press