The biggest individual disclosure by a taxpayer was $30 million in income $120 million in assets that had been held in Liechtenstein and Switzerland. The smallest was a disclosure of $10,000. Only 130 individuals made declarations about property. The vast majority of voluntary disclosures were related to income and shares. But the Tax Office said some people were still not getting the message and would be hunted down to face heft penalties and possibly jail. Separately the agency has been handed information about a local bank with 2000 Aussie clients who have accounts in Vanuatu.

The Tax Office is also using powers offered under Australia's new treaty with Switzerland to request information from Swiss authorities to help them gather a case against five rich people that the ATO suspect have hidden income and assets offshore but who have not been cooperating. The Tax Office amnesty, which ends next week, was introduced by Tax Commissioner Chris Jordan earlier this year to try, once and for all, to get rich family secrets out in the open. It will be the last amnesty ever offered in Australia, and comes as world tax authorities, including the Swiss, cooperate more closely with Australia and other OECD and G20 nations on greater information sharing. Switzerland proved to be the most popular destination for undeclared wealth (585 individual disclosures were made about money and assets hidden there), followed by the UK (299 disclosures), Israel (231 disclosures), Singapore (123 disclosures), Hong Kong (115 disclosures) and Liechtenstein (43 disclosures). ATO deputy commissioner Michael Cranston, who looks after the high-wealth individuals unit, said with just one week to go, "this is your last chance [to come clean]. "If you don't, the sanctions will be ... tax, penalties and potential criminal action," he said.

Mr Cranston confirmed that most of the people who had come forward were the children and grandchildren of rich migrants families. They had been left to clean up tax messes inherited from their migrant parents and grandparents, who upon migrating to Australia in the 1950s and 1960s, had stashed money away in secret Swiss bank accounts - a practice that was common at the time. "It's a clean-up exercise of the past," Mr Cranston said. The majority of those involved are wealthy Australians, classified by the Tax Office as having with net assets greater than $5 million, and high-wealth individuals with net assets worth more than $30 million. Mr Cranston said the bulk of disclosures related to "managed type investments, securities, interest bearing accounts and dividends".

The amnesty, which was first revealed in January and officially announced by the Tax Office in March, gives reduced penalties and caps penalties back on to four years, not the entire time money and assets have been hidden. Those making voluntary disclosures have also been given an assurance that they will not be investigated or referred for criminal investigation on the basis of that information. Initially taxpayers that were caught up in official ATO audits were prohibited from participating in the amnesty, dubbed by the agency as "Project Do It". But "we've allowed a couple in for various reasons because the audit was on small minor matter and had nothing to do with ...international arrangements," Mr Cranston said. ATO assistant commissioner, international, David Allen, said a recently updated treaty with the Swiss had greatly increased their powers to hunt down individuals dodging tax. On top of this, the OECD and G20 are working on a common reporting standard that will see information held by banks and other financial institutions shared between tax authorities. Mr Allen said the Tax Office would be undertaking its first information exchange with Swiss authorities under the new treaty on December 22nd, just days after the amnesty closes (on December 19).

"That first request is about a series of (five) high-wealth individuals that have we have concerns about and that we suspect may have a Swiss bank account," he said. "We also have an informer via a treaty country that has given us a list of Australians with Swiss bank accounts. There's 122 names on the list. This is significant as its first time we've made a request for information and we are confident that they [Swiss authorities] will supply the information that we need. This is not a fishing expedition." He said the agency had also separately been given information from a bank detailing 2000 Australians with accounts in Vanuatu. "We will use that to determine whether they are correctly reporting offshore income," he said. The head of law firm Arnold Bloch Leibler, Mark Leibler, who advises the nation's wealthiest people and has made a number of lodgements on behalf of his clients for the amnesty, said it had been "incredibly successful". "I think in the end, it will be what I had predicted, and there will be billions brought back [into the tax net]," Mr Leibler said. "There's been a last-minute spate of people who have lodged expressions of interest with my firm. A lot of them felt it was too good to be true."

Mr Leibler said the majority of clients had shares and money in Swiss bank accounts that had been sitting there for decades. Only a few had property offshore. Aside from Switzerland, he said other countries where income and assets were hidden included Hong Kong, Israel, Liechtenstein, the Bahamas and Panama. Per client, the amounts varied "from a couple of million of dollars to tens of millions - big amounts of money", he said.