Nicholas Schofield, 46, abused his position as the manager of Indigenous Business Australia's finance systems to steal taxpayers' money, which was supposed to fund business and home loans designed to reverse Indigenous disadvantage.

Schofield's actions were calculated and his methods sophisticated. He managed to copy previous loan transfers to legitimate vendors, but changed details to funnel the money to himself. He then used his seniority and experience to cover his tracks.

The money was used to buy an Aston Martin, a Mini Cooper, expensive clothes, jewellery, and a $10,000 custom doll house Schofield wanted for himself.

When police finally caught up with him, he told them it was "a bit sad" that it had actually worked for so long.

His crimes were uncovered following an audit of IBA that highlighted discrepancies with a number of transactions.

He initially denied any wrongdoing, but eventually gave himself up.

Schofield told his boss: "I'm not coming into work today. I took the money."

Schofield was charged with eight offences, each relating to a separate transaction. He pleaded guilty,and has since shown remorse, accepted responsibility, and acknowledged the impact of his crimes.

Schofield told the author of a pre-sentence report he had always known he would be caught.

In the ACT Supreme Court on Tuesday, Justice John Burns sentenced him to five years' imprisonment, with a non-parole period of three years.

Justice Burns said the organisation had placed its trust in Schofield and he had repeatedly breached it.

Schofield, in his senior position at IBA, was already on a salary of $113,000.

"You largely used the proceeds of your offending to fund a lavish lifestyle," the judge said. "Your motive for committing these offences was simply greed."

He will be eligible for release in October 2018.