A Wellington man accused of duping at least 30 New Zealanders out of millions of dollars appears to have got away with what his victims claim was an elaborate scam.

The Serious Fraud Office has confirmed it is not pursuing Grant Cardno, five months after the Herald revealed he was working as a petrol station attendant in Otaki, using the name "Tom".

Mr Cardno, who has previously claimed to have a knighthood, was one of several people named five years ago by United States authorities as being part of a Ponzi scheme involving up to US$390 million (more than $500 million at today's exchange rates) from more than 1400 American investors.

He didn't turn up in court to defend himself and in 2006 a Texas judge found against his company, Sovereign Capital Investments, by default.

According to US authorities, Sovereign was involved in "fraud, deceit and a deliberate or reckless disregard of regulatory requirements" which "directly or indirectly" resulted in substantial losses to investors. The other defendants in the case, who were American, went to jail.

Dozens of New Zealanders who invested millions of dollars in Sovereign and in another of Mr Cardno's companies, Liberty Establishment, also claim to have been duped by Mr Cardno.

One investor, who wished to remain anonymous, said yesterday that he had long ago given up on ever seeing his money again.

But he and at least 30 other investors would still like to see justice done.

An SFO investigator had called him following the Herald story, but he had heard nothing since.

"I'd like them to follow up on it," he said. "Otherwise what kind of message does it send?"

SFO head Adam Feeley said yesterday that he was unaware of any ongoing investigation, or any official complaint by investors.

A Herald investigation revealed that Mr Cardno once helped to host an investment seminar in Fiji attended by Act MP Rodney Hide.

Mr Hide was a speaker at the 1999 event, run by a firm called Investors International. According to people who attended, Mr Cardno was the master of ceremonies.

Some of the event's organisers later went to jail for their part in a Ponzi scam alleged to have fleeced more than 150 New Zealanders of about $10 million.

At one stage, Mr Cardno built a multimillion-dollar home on Norfolk Island, designed by a New Zealand architect. The house burned down in mysterious circumstances in 2003.

Mr Cardno, who is the brother-in-law of Destiny Church spokeswoman Janine Cardno, also claimed to be involved in a charity called the Hope Foundation, and claimed to have links to the "Millionaires of the World Club".

He was once linked to Remuera couple Mike and Jackie Bradley, whom the Serious Fraud Office suspects of also running a Ponzi scheme.

In March, he told the Herald his knighthood was an informal arrangement from the "Queen of England", for his work in a Wellington soup kitchen.

He denied defrauding anyone, and said he was sick of being used by "other people". He said his lawyer was trying to overturn the fraud judgment against him in the US.

The SFO has recently come under fire from supporters of South Island businessman Allan Hubbard for its decision to launch an investigation into his financial affairs.

Mr Feeley refused to comment on the outcome of that investigation this week, but it is understood the Government is bracing itself for the possibility that it will not find any evidence of complex fraud.

However, Mr Feeley insisted this week that the office intended focusing on large-scale investment frauds as one of its top priorities.

His comments followed the sentencing of a Nelson man found guilty of cheating nearly 500 investors out of $5.3 million by falsely claiming to have invented a revolutionary form of data compression.

Philip James Whitley was sentenced to a jail term of five years and three months, three years after the SFO began investigating him.