The ACT Supreme Court has heard there was no obvious explanation for why a former CSIRO executive spent more than $300,000 of government money on cars, a jet ski and a gym membership.
Mark Wallis, 47, pleaded guilty to three charges, including using his corporate credit card for personal purchases and forging a document.
The fraud was discovered five years ago, around the time he left the CSIRO, at first on sick leave.
The court heard he had not been getting along with his immediate manager and he complained of bullying.
Wallis joined the CSIRO in 2011, and left about 2017, when his final salary as a senior manager was approximately $250,000 with allowances and a bonus.
The court heard the AFP investigation into Wallis, targeted unreconciled expenses on his credit card.
When a formal notice of misconduct was sent to him, he rang a CSIRO officer leaving a long phone message denying any wrongdoing.
"I don't know how those have been placed on my credit card," he said.
He said he was also disappointed by the approach taken by the CSIRO.
"You know a phone call could have been appropriate … which would have been nice, as opposed to a formal notice of misconduct," he said.
Wallis also offered to repay the money.
But in a later conversation, he admitted the expenses were all his.
Wallis's lawyer Margaret Jones conceded it was a serious amount of money, but said there were no factors like gambling which would have suggested a motive.
The court heard Wallis had been receiving psychiatric help, after struggling during his time at CSIRO.
Witnesses also told the court he had had a serious motorbike accident in 2010, which had seemed to alter his personality.
The prosecution said the scale of the theft warranted a full-time custodial sentence.
But Ms Jones urged the court to consider an intensive corrections order.
Wallis will be sentenced later in the year.
