IT giant IBM has admitted using leaked rival information to help secure a multi-million dollar Queensland Health payroll contract.
An inquiry into the bungled system is investigating whether IBM, which eventually won the contract, was given an unfair advantage during the tender process.
The probe was triggered after thousands of public servants were underpaid, overpaid or not paid at all following the system's implementation in March 2010.
The blunder is expected to cost taxpayers $1.2 billion.
IBM executive Lochlan Bloomfield has admitted to the inquiry he was forwarded an email from rival bidder Accenture about its proposal during the tender process in August 2007.
However, he says he can't remember who sent it, why he removed the sender's name when forwarding it to a colleague, or whether he reported it to his superiors.
But Mr Bloomfield says he is sure he never requested it.
"I would remember if I asked someone to get this intelligence for me," he said.
He said he would have taken the source's name out of the forwarded email because it was "not relevant" - not because he was trying to protect his identity.
Under sustained questioning from counsel assisting the commission, Peter Flanagan, Mr Bloomfield conceded he had used the information to highlight comparisons between Accenture's pricing structure and IBM's.
Accenture had initially been the preferred provider.
The inquiry is also expected to hear on Tuesday from outside contractor Terry Burns.
CorpTech, the Queensland Government's IT arm, appointed Mr Burns to review the whole-of-government IT systems, which led to the payroll overhaul.
Mr Burns' role in the system's failure has regularly been called into question during the inquiry.
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