Virendra Rastogi, one of the SFO's high profile convictions
The conviction rate in cases brought by the Serious Fraud Office (SFO) rose in the past year from 61% to 68%.
The SFO's annual report says 17 of the 25 individuals it prosecuted were convicted, in seven completed trials.
The most high-profile success involved jail sentences for three directors of the Independent Insurance company, which had collapsed in 2001.
The SFO said its conviction rate was higher than the average of 61% for the past five years.
Its success rate is now close to the long-term average of 69% going back over the 20 years since the SFO's inception.
The new director of the SFO, Richard Alderman, warned that the cases it investigated, usually involving sums greater than £1 million, or cases of national significance, were not just confined to frauds against large organisations.
"The types of fraud we investigate are as varied as the victims of those frauds: major corporations, small businesses, the investing public, state-funded schemes and overseas exchequers," he said.
"The lives of individuals - taken in when they are often at their most vulnerable through age or bereavement - are often destroyed," he added.
Since the end of the financial year, the SFO has obtained further convictions in cases against the bogus metal trading firm RBG Resources, and against Severn Trent Water for providing false leakage data to the water regulator Ofwat.
However, the SFO's report makes it clear that small private investors are still falling victim to very significant frauds.
Of the cases currently being prosecuted in the courts, four involve allegedly bogus investment schemes and another one involves illegal share-selling operations known as "boiler rooms".
The SFO highlights the increasing burden of prosecuting complex frauds, because of the sheer volume of evidence involved.
It has had to establish a special unit devoted to finding information hidden on digital devices such as computers, mobile phones and iPods.
"We use computers too, to help us manage the massive and increasing documentation associated with complex fraud cases," said Mr Alderman.
"Indeed, one of our cases, stored on its own computer bank, contains 130 terabytes of information - the equivalent of 130,000 truckloads of paper," he pointed out.
The SFO report mentions only briefly the most controversial aspect of its work in the past year - the decision by its former director, Robert Wardle, at the end of 2006, to drop its investigation into allegations of corruption involving arms deals between BAE Systems and the Saudi Arabian government.
In April, two High Court judges said that decision had been unlawful and an "outrage" and had been caused by blatant threats from the Saudis.
The SFO has since appealed to the House of Lords against that ruling and is waiting for a judgement.