A reclusive millionaire with a secret treasure trove of gold and silver may face perjury charges after fleeing to the other side of the world to escape a debt he didn't want to pay.

Psychiatrist Alan Geraint Simpson, originally from Britain, hid a $3.5 million fortune from authorities, most of it in safes and secret passages throughout his Hamilton home.

His secret wealth was in contrast to his English bankruptcy. He told insolvency officers he was a retired church-going gentleman, raising a teenage daughter on a pension of $344 a week.

In a legal-world first, Kiwi insolvency investigators traced "a truckload of gold and silver", money in overseas accounts and other cash hidden under an alias. Their work is now being used internationally as a legal model on tracking down bankrupts who try to hide money.

A decision is pending from the police legal team over whether Dr Simpson misled the court over the ownership of $2.3 million in bullion and the false name used to hide it. Waikato police detective Simon Eckersley said the investigation - started at the request of a High Court judge - had been completed and was currently with the police legal section.

An outcome was expected within a fortnight.

The Herald was given the first full access to the court file of the case this week. It revealed English insolvency officials approached the High Court, asking it use a new law allowing bankruptcy proceedings to cross borders. They told Justice Paul Heath that Dr Simpson had debts in England but hidden assets in New Zealand.

Justice Health granted the order, making Official Assignee Les Currie and his team responsible for investigating the case. He later praised Mr Currie and his team for their insight and precision linking $3.5 million of hidden wealth to Dr Simpson.

Using a search warrant, Mr Currie and the police specialist search team found gold, silver and precious coins inside specially constructed bunkers and hidden safes. They searched the house twice, going back after Mr Currie received a tip leading to a builder who created bunkers inside the home. Among the hiding places was a seamless panel covering a cavity in the floor beneath the dining-room table.

Mr Currie then linked the bullion to the bankrupt, cut through shell companies which hid wealth and found evidence to turn over an alias shielding about $400,000. In the end, Dr Simpson's wealth was brought from almost every hiding place - and used to pay off debts of $2.45 million.

The international assistance didn't cost taxpayers a cent - Mr Currie recouped the $500,000 cost of the investigation. Court documents show Dr Simpson was even charged for the cup of coffee he drank while watching his house being searched.

Justice Heath said more than $2 million in gold and silver had been found, along with $37,500 in cash and $1 million in overseas accounts. Asking for a perjury investigation, the judge said: "Mr Simpson denied [on oath] that the items seized were his."

He also took issue with Dr Simpson's evidence over the name "James Walter Smith".

A bank account in that name in England held about $300,000.

Asked if he knew someone of that name, Dr Simpson said: "He used to be the manager of the Hilton Hotel in Hong Kong."

Justice Heath asked police to "investigate whether there is evidence of perjury", pointing to the evidence on the bullion's ownership and Dr Simpson's denial he used the Smith alias.

Dr Simpson left Hamilton this year with about $1 million, moving to Auckland.

Lawyer Victoria Mann acted as a trustee of his holdings.

Ms Mann said Dr Simpson had returned to Britain.

She said she no longer had anything to do with him. "I want nothing more to do with the case."