By Pattrick Smellie

May 30 (BusinessDesk) - Police investigating a leak of sensitive Budget information have determined that the Treasury's computer system was not 'hacked'.

In a rocky start to what should have been a showcase day for the government's first 'Wellbeing' Budget, a flurry of press statements issued around 5am confirmed that the police had determined the way the information was obtained was "not unlawful".

Treasury Secretary Gabriel Makhlouf announced he had now sought an investigation from the State Services Commission, which oversees the public service.

State Services Commissioner Peter Hughes said he was considering his options.

The statements come ahead of an 8.45am media briefing this morning at which National Party leader Simon Bridges is expected to detail how the National Party came by the information as speculation mounts that the party gained access to a Treasury website that was being set up privately to house Budget information. A parliamentary IP address was among those found to have accessed a 'cloned' Treasury website where Budget materials were being uploaded in what was meant to be a private environment.

"The clone also copies all settings for the website including where the index resides. This led to the index on the live site also containing entries for content that was published only on the clone site," said Makhlouf. "As a result, a specifically-worded search would be able to surface small amounts of content from the 2019/20 Estimates documents."

Cyber-security experts have suggested 'crawler' software and a conventional search engine may have been all that was necessary to reveal the information if the Treasury site had security flaws. National MPs in Parliament yesterday appeared to know that the information had not been hacked, pursuing questions into both Treasury's and Finance Minister Grant Robertson's competence.

"Our systems were clearly susceptible to such unacceptable behaviour, in breach of the long-standing convention around Budget confidentiality, and we will undertake a review to make them more robust," said Makhlouf, who has less than a month to run in his eight-year tenure as head of the government's lead economic advice agency.

The Budget is due to be delivered at 2pm, but may be overshadowed if, for example, resignations by senior officials or - at a stretch - an offer of resignation from Robertson were to be made.

Finance Minister Roger Douglas offered to resign after the 1986 Budget was distributed early to several dozen prominent New Zealanders. Then Prime Minister David Lange declined Douglas's offer.

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