The lengths Simon Bridges went to find out who leaked his travel expenses

Newshub can reveal National Party leader Simon Bridges pressured police to release who leaked his travel expenses to Newshub - but they turned him down because it put the safety of the leaker at risk.

An email sent from the National leader's Chief of Staff Jamie Gray on August 27, 2018 to Police Commissioner Mike Bush shows an urgent Official Information request made for "any information NZ Police holds about the identity of the person who sent the text message purporting to be responsible for the unauthorized release of Hon Simon Bridges' travel expenses to Newshub".

The strongly worded letter exclaims that it's "illogical that NZ Police have the identity of this person, but have not released that information to National. It is unnecessary and a waste of taxpayers' money to require National and the Parliamentary Service to undertake an investigation when NZ Police know who the person is".

The impact of the expenses leak on National MPs and their public perception was raised: "It is widely being portrayed as being the work of a National MP, and this is causing concern amongst the National caucus, as they feel their reputations are being called into question".

The letter also claims the public interest outweighs the right of the individual's privacy.

The lengths Simon Bridges went to find out who leaked his travel expenses
The lengths Simon Bridges went to find out who leaked his travel expenses

The Police Commissioner's Chief of Staff responded a day later, detailing police's correspondence with the person involved and how they went about confirming their identity.

Police engaged a medical practitioner, who dealt with the individual's mental health. Due to concerns for the wellbeing of the individual, police declined Bridges' request, saying releasing their identity would "endanger the safety of the person involved".

"Police relies on s 6(d) of the Official Information Act, namely that making the information available would be likely to endanger the safety of the person involved in this matter." 

Mr Bridges' claim of public interest in the matter was also rejected by Police.

"Police also relies upon s 9(2)(a) of the Act, in that withholding the information is necessary to protection the privacy of the individual concerned. Police has weighed the public interest considerations, and in the circumstances, has determined that that these do not outweigh the privacy considerations."

Police also confirmed the person who leaked the travel expenses didn't commit any criminal offence by doing so.

The lengths Simon Bridges went to find out who leaked his travel expenses
The lengths Simon Bridges went to find out who leaked his travel expenses

When asked for an interview, Simon Bridges was unavailable for comment. In a statement, a National Party spokesperson responded to Newshub's request.

"We were clear that we wanted to identify the person who sent the text message for reasons including that we had concerns for their wellbeing," the statement read.

"We requested the identity through the right channels as was our right and Police declined as is theirs and we respected that decision."

Simon Bridges' expenses leak: how did it all happen?

Newshub's Political Editor Tova O'Brien was leaked Mr Bridges' expenses on or before August 13. The information showed Mr Bridges had spent $113,973 on travel and accommodation during his road show.

A parliamentary inquiry was called by Speaker Trevor Mallard, who later cancelled the investigation, saying evidence showed it was a matter for the National Party. He then quietly pushed on with his own investigation.

Someone claiming to be the leaker had sent a text to Mr Mallard, Mr Bridges and Newshub calling for the inquiry to be stopped due to ongoing mental health issues. Mr Bridges decided to continue with the inquiry.

Newshub was then leaked an internal email sent to staff on September 25 saying the investigation will include those who don't work in Parliament.

The final PwC report did not identify the source of the leak. It said evidence pointed to Jami-Lee Ross but there wasn't certainty in the findings. Simon Bridges went with it.

Mr Ross has repeatedly denied he leaked Mr Bridges' expenses and fired back by releasing a number of secret recordings of National leader and made allegations of electoral fraud. He took his claims to Police.

Still leaking

Simon Bridges' leadership has been under growing pressure. New leaks to media surfaced last week from an anonymous source claiming to be a National MP.

The leaks detail areas of policy National is looking at exploring before the 2020 election, including an income insurance scheme.

Internal poll numbers and media talking points were also released.