Assistant Commissioner Neil Paterson, head of Victoria Police's Intelligence and Covert Support Command, has been named as the first witness when public hearings before Commissioner Margaret McMurdo begin next Wednesday.

A number of past and present police officers will appear as witnesses.

Gangland barrister Nicola Gobbo, also known as Lawyer X, worked as a police informant from 1995 until 2009 while also representing high-profile clients.

After Mr Paterson's evidence, the royal commission will focus on a period starting before Ms Gobbo's role as informer began.

"The focus of the hearings will then be on Victoria Police's dealings with Nicola Gobbo between 1993 and 2000," a statement from the commission said.

The royal commission will inquire into the number of, and extent to which, cases may have been affected by Ms Gobbo's conduct.

It will also examine the force's use of informers who are subject to legal obligations of confidentiality or privilege.

Anyone represented by Ms Gobbo who believes their case may have been affected by her informer role, has been invited to make submissions.

Ms Gobbo's secret identity was unveiled by a court this month, following concerns the royal commission into police use of legal figures as informers - including murdered lawyer Joe Acquaro - would be hindered if she could not be named.

Known to police as Informer 3838, Ms Gobbo counted drug lord Tony Mokbel and gangland figure Carl Williams among her clients and by her own admission, her information helped convict hundreds of gangland criminals and drug traffickers.

Her clients learned of her double life in recent months and a number now plan to appeal significant jail terms, including Mokbel who was recently stabbed in jail and convicted drug trafficker Robert Karam.

On Wednesday, Richard Barkho, who has a child with Ms Gobbo, tried to appeal against the five-year jail term he received in July 2014 for trafficking more than 2.5kg of ice.

His legal team claimed he faced extra hardship in prison and there were concerns for his safety because his partner was a much-publicised police informant, "who visits him still".

The High Court has said Ms Gobbo's conduct was an "appalling" breach of her obligations, that Victoria Police managed her in a "reprehensible" fashion and every corrupted conviction will have to be re-examined.

Ms Gobbo became a barrister in 1998 and ceased to practice on June 30, 2009.

Australian Associated Press