The documents revealed a secret plan to provoke nurses into industrial action so it could force them into arbitration and force job losses.

The pursuit of the whistleblower was uncovered after an eight-month freedom of information chase to obtain the Department of Premier and Cabinet's records on non-compliant use of almost $1.25 million across a dozen projects since 2007.

The leak investigation began on November 9, 2011, three days after the media report, and blew out the initial $150,000 estimate by $40,000 and an estimated three months. Two senior members of the government team that commissioned the investigation had declared conflicts of interest without preparing plans to manage their conflicts, the government's records show.

Another of the projects involving cost blowouts - which the state government tried to withhold on the grounds it would ''cause damage to the international relations of the Commonwealth'' - was the Queen's visit to Melbourne in 2011. The contract to plan events for the the royal visit was exempted from public tender and ran over budget by more than $50,000 due to unforeseen circumstances.

The details of those circumstances remained blacked out in the final version of the document released to The Sunday Age.