A U.S. citizen who was recently a senior executive at the Commonwealth Bank of Australia pleaded not guilty in a Sydney court Wednesday to charges that he accepted bribes to award a contract to a U.S. information technology firm.

Keith Robert Hunter, 61, formerly of San Francisco, and his alleged accomplice — another Sydney-based American who has not been named — were allegedly paid $2.19 million for awarding a bank contract to ServiceMesh without a tender, according to court documents.

The contract was worth "tens of millions of dollars" and would have contributed to ServiceMesh's sale price when it was bought by Virginia-based global giant Computer Sciences Corp. in 2013, the documents stated.

The bank, one of Australia's largest, fired Hunter and his alleged accomplice late last year. The accomplice returned to the United States after Australian police froze more than $1.5 million in a bank account.

When Hunter was confronted last year by bank investigators about suspicious money transfers from a foreign company into his personal account, he allegedly fired off an email to his accomplice.

"I want to vomit. I cannot believe we were tis (sic) stupid," Hunter wrote, according to police evidence tendered to the Sydney Central Local Court.

Hunter, who had previously held senior positions at global corporations Visa Inc. and J.P. Morgan, was arrested at his Sydney apartment on Tuesday.

He pleaded not guilty to two counts of bribery. Each carries a potential maximum sentence of seven years in prison.

He was released on bail on condition that he surrender his U.S. passport and report to police daily. He appears next in court in April.

ServiceMesh had been involved with the bank since 2009. When Hunter joined the bank as information technology executive general manager in 2011, ServiceMesh's part-owner Eric Pulier contacted him by email about the company's relationship with the bank, according to the police evidence given to the court.

The $2.19 million was paid to Hunter and his alleged accomplice, another IT executive at the bank, after ServiceMesh was sold to CSC, according to the evidence.

The money was paid through a California-based shelf company Ace Inc. which had been set up by ServiceMesh, police evidence said.

When questioned by bank investigators, Hunter and his alleged accomplice said the payments from Ace were for consultancy work.