An announcement by the UK's HM Revenue and Customs (HMRC), and the Australian Tax Office (ATO) on Tuesday revealed that the tax authorities in Australia, Canada, France, Italy, New Zealand, Sweden, United Kingdom, the United States of America, as well as several other un-named countries, are all taking part in the investigation.

HMRC confirmed that it has opened enquiries into UK residents who have Liechtenstein accounts to establish whether the accounts have been disclosed for tax as UK law requires, but stated that it believes that many have not been disclosed.

HMRC Acting Chairman Dave Hartnett commented:

"Tax evasion is not a victimless crime. Honest citizens have to meet the cost of the tax that is evaded by a minority who are dishonest. Tax cheats deprive our public services of vital funding."

He continued: "Everyone is entitled to conduct their financial affairs in privacy but secrecy laws which facilitate tax evasion are completely unacceptable. Those who have hidden their income and gains from HMRC should come forward and make a prompt and complete disclosure."

"In the light of recent developments involving Liechtenstein bank accounts, there needs to be a significant move towards full implementation of OECD standards on transparency and effective exchange of information in tax matters."

Meanwhile, Australian Tax Commissioner Michael D’Ascenzo disclosed on Tuesday that the ATO has already issued notices to produce information and has conducted "unannounced access visits" with Australians who have suspected links to Liechtenstein accounts or legal entities.

“In Australia, there are 20 audit cases underway relating to funds in Liechtenstein ranging from AUD200,000 to millions of dollars,” D’Ascenzo revealed, adding that: “These are ongoing inquiries and the final tax bill is still unclear."

He continued: “We are committed to ensuring there is a level playing field for people who do the right thing and have therefore increased our focus on Australian taxpayers who have abusively used offshore bank accounts, offshore financial products, offshore tax arrangements and/or offshore structures.”

In a bid to tempt voluntary disclosures from taxpayers with offshore accounts, D’Ascenzo has encouraged the use of Australia's offshore voluntary disclosure initiative.

“Taxpayers who contact us before they are the subject of an audit and make a full and true disclosure may be entitled to substantial reductions in shortfall penalties," he stated.

The ATO has already received 425 submissions, disclosing AUD17.5 million (USD16.4 million) in income.

According to HMRC, all the countries now working together were represented at the FTA's September 2006 meeting in Seoul, Korea, when Tax Commissioners from more than 30 countries identified the use of tax haven bank accounts as a major threat to successful tax administration.

The HMRC statement explained that tax commissioners will continue to re-examine the effectiveness of the measures in place to protect tax bases and to consider whether new measures might be needed. At the FTA 2008 meeting in South Africa, the Commissioners agreed to study the role of banks in tax compliance.