The Revenue Commissioners has collected more than €30 million in unpaid tax and penalties as part of an ongoing inquiry into the financial affairs of more than 500 medical consultants.

Officials have found that many had set up  “controlled companies” to maximise their incomes but which were found to be involved in aggressive tax planning and avoidance.

The largest single settlement to date has been almost €2 million following the investigation of more than 200 consultants.  It is in the process of investigating some 300 other individuals.

The bulk of cases investigated to date are focused in Dublin but the inquiry has since been expanded nationwide.

Internal Revenue records indicate that while just a handful of consultants have been named in defaulters lists, the number is likely to grow significantly over the coming months as new cases are closed.

The inquiry has focused on liabilities arising from moves by medical consultants to set up private companies to maximise their income.

But investigations by Revenue indicate that many of these entities were used to cut their tax bills by deducting large expenses – which had little to do with their business activities – and to improperly write off losses against capital gains taxes.

In many cases, these companies had “little or no commercial reality or validity”, and involved “unacceptable aggressive accounting or taxation practices”.

Details of the investigation are contained in Revenue records released to The Irish Times under the Freedom of Information Act.

The Irish Medical Organisation told members in recent months that the Revenue had widened its investigation into tax compliance issues involving consultants.

As each consultant has individual taxation arrangements, it recommended members to consult with their tax advisers or accountants.

The extent of the probe is also likely to raise questions over the role of accountants and tax advisers who were involved in promoting these schemes.

Unprompted disclosures

Some medics have said privately they sought financial advice they believed to be legal and tax compliant but are now left with hefty tax bills.

The Revenue says it is also challenging tax advisers or agents involved in designing the schemes.

The authority has warned medics who are not yet the subject of an audit that they still have the option of making “complete and unprompted” voluntary disclosures and avoid publication in its defaulters list.

Latest figures show that wider investigations into white-collar professions – such as doctors, dentists, accountants and lawyers – have yielded tens of millions of euro in tax and penalties for the exchequer. These cases typically involve the under-declaration of income, improper use of tax reliefs and other measures.

Data compiled for the first four months of this year shows that the rental sector has accounted for one of the biggest sources of unpaid tax.

Some €10 million was recovered from landlords between January and April, as Revenue target their audits on taxpayers based on new data available from the property tax register and the home renovation incentive scheme.