Keith Robert Hunter was being confronted by Commonwealth Bank investigators about suspicious transfers from an overseas company when he fired off an email to a colleague.
"I want to vomit. I cannot believe we were tis (sic) stupid," the IT executive allegedly wrote last year, according to police facts tendered in court on Wednesday.
The man on the receiving end of that email was Hunter's IT engineering colleague, who was also questioned about international transfers into his personal account in 2014.
On Tuesday Hunter, 61, was arrested at his Sydney unit, accused of granting a US-based IT firm a lucrative contract without putting it to tender and receiving payment in return.
The US company - ServiceMesh - was sold for "hundreds of millions" of dollars to a publicly listed company in 2013.
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Detectives allege the Commonwealth Bank contract - worth tens of millions of dollars - with ServiceMesh would have contributed significantly to the value of the IT company's sale, according to police facts tendered in court on Wednesday.
Hunter, who previously held senior positions at global corporations Visa and JP Morgan, pleaded not guilty in Central Local Court to two counts of bribery.
His former colleague allegedly fled the country to the United States after police froze $US1.5 million ($A1.96 million) million in suspected corrupt payments.
When Hunter started with the bank as an IT executive general manager in 2011, he allegedly got an email from ServiceMesh's partial-owner Eric Pulier outlining the "lay of the land at CBA', the facts state.
ServiceMesh had been involved with the CBA since 2009.
Police facts state Hunter and his colleague allegedly received payments of $2.19 million after ServiceMesh's sale.
The alleged corrupt payments were made through a California-based shelf company - Ace Inc - set up by ServiceMesh to launder the money, police say.
LinkedIn later revealed to detectives Mr Pulier was a founding donor for Ace Inc, the facts state.
When questioned, Hunter and his colleague stated the payments from Ace were for consultancy work.
Police allege the pair had hefty salaries at CBA and their "experience and advice" was critical in providing direction to the senior bank executives and boards.
Both men were fired late last year.
Hunter was granted bail on Wednesday on the condition he surrender his US passport, report to police daily and not enter an airport.
Outside court his lawyer Bryan Wrench said Hunter was "the only person who has decided to fight the case in Australia".
Hunter's case was adjourned until April.
