The company chief executive who blew the whistle on fraud by Christchurch businessman Gavin Bennett said she first suspected something was wrong when his behaviour changed.
Bennett, the former director of IT company Datasouth, was on Thursday jailed for eight years for fraud involving over $100 million.
He admitted running a Ponzi-style scheme using loans from the now failed South Canterbury Finance to fund a high-flying lifestyle.
The Serious Fraud Office (SFO) has praised Datasouth chief executive Hayley Bryan for her courage in reporting the fraud.
Ms Bryan told Radio New Zealand's Nine to Noon programme Bennett behaved irrationally when he heard about the collapse of South Canterbury Finance.
Ms Bryan says she was sickened to make the discovery that, at the time when people in Christchurch were struggling with the trauma of the Canterbury earthquakes, Bennett was leading a lavish lifestyle in Australia.
"We had staff that were under a lot of pressure, clients that were under an incredible amount of pressure and really relied on us to keep their IT systems running, and he was just focussed on milking money,"
Ms Bryan says South Canterbury Finance did not pick up the fraud for several years because Bennett always paid interest on the loans on time.
SFO chief executive Adam Feeley told Checkpoint the office was extremely grateful to Ms Bryan for her very brave decision in reporting Bennett.
"She was relatively new in her job in an apparently successful IT company and suddenly she realised things were not what they appeared and she had to challenge her managing director," Mr Feeley said.
"(Bennett) bullied her, he tried to hide it. That's an incredibly hard decision to go up against your managing director with possibly the nagging doubt that her suspicions were not well founded."
Mr Feeley said the most immediate victims were the Datasouth staff trying to keep the company afloat, and whose thanks from Bennett was to become unemployed just after the Christchurch earthquake.