Conceding that authorities cannot ''chase every rabbit'', senior tax officials have told Fairfax that the new outfit is designed to hit big-time fraudsters, attract more publicity and team up more often with police, the Immigration Department and welfare agencies.

The cash-strapped Tax Office, in the process of shedding 900 jobs, insists the move is not about cutting costs.

Deputy Taxation Commissioner Greg Williams says the giant new division will take a new approach to ''case selection'' hoping to change the behaviour of companies and individuals through high-profile big-money busts.

The move will allow the ATO to step up operations against complex rackets such as those run by some labour hire firms supplying undocumented foreign nationals as harvesters for Australia's fruit-growing regions, and pocket millions of dollars in unpaid GST, payroll tax and superannuation.

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Tax Office insiders have been critical of the ATO's response to the problem, alleging authorities had ''admitted defeat'' in the battle against the fraudsters, many of them from mainland China who have been known to put millions of dollars through Australian casinos before moving the money offshore.

But the Tax Office has defended its record in the battle against the labour-hire rorts, citing about 300 audits on firms in the past two years that have clawed back $76 million.

The new operation will bring together three major ATO anti-evasion units: Serious Non-Compliance, Aggressive Tax Planning and Private Groups and High Wealth Individuals, which takes in the new unit and is the outfit behind the Wickenby operation against Paul Hogan and other high flyers.

Mr Williams said the move would end the ''bottom-up'' approach in which targets for investigations were chosen by relatively junior managers.

''We had a lot of bottom-up work going on and people in picking cases would see something and they would say, 'This is something we should respond to','' the deputy commissioner said.

But Mr Williams, the boss of the ATO's serious non-compliance force, said he now wanted his troops carrying out investigations ''that people will pick up in the media, that from an industry point of view will touch a chord with people, that will have multiple agency tentacles so you can get a whole of Commonwealth approach''.

''The more you work closely with other people on things that are joint, the opportunities just present themselves like you would never have seen them before,'' he said.

Mr Williams said that cases would not be high priority unless they were going to change behaviour in broad industry sectors or among wealthy individuals.

''If you're not going to get a media response to it and a leveraged response to it and it doesn't have broader implications, then you'd say, 'I could quite easily spend 12 months doing it and I'll raise some tax revenue but I'm never going to solve the problem','' he said.

''It's a whole raft of strategies, from marketing and communication, through to working with partner agencies through to criminal investigations.''

He cited as a template for the future a case in South Australia in 2013 in which the ATO and federal police raided 80 businesses and worked with immigration, welfare and workplace authorities as well as Commonwealth prosecutors.