Labour is calling for "high powered" independent inquiry into the way politically-charged cases are handled, saying the police decision not to prosecute John Banks needed to be investigated.
The call comes after the Act MP was found guilty last week of filing a false electoral return following a private prosecution by retired accountant Graham McReady, launched after the police claimed in 2012 there was not enough evidence to prosecute.
Labour's justice spokesperson Andrew Little said the Government should launch an inquiry into why the police failed to prosecute, as well as into the way previous politically-charged cases had been handled, in order toensure the integrity of the electoral system."
John Banks has now been found guilty of electoral fraud, with a high court judge finding the Act MP had made false declarations about donations from Kim Dotcom after his failed mayoral campaign," he said.
"During the procedural wrangling after the private prosecution was launched, every other judge that looked at the initial information found there was a case to answer, but the police and their crown law advisers didn't."
Little questioned whether the case against Dotcom, who faces accusations of copyright infringement and fraud as well as possible extradition to the US, had in any way affected the decision not to prosecute Banks.
The case against Banks centered on a $50,000 donation from Dotcom which the Crown alleged Banks had asked to be split into two $25,000 donations so they would appear anonymous and which he could deny knowledge of.
Little compared the handling of the investigation to the complaint laid by Prime Minister John Key against cameraman Bradley Ambrose over the teapot tapes in 2011 which recorded a private conversation between Banks and Key in an Auckland cafe.
Key claimed the conversation was deliberately recorded by Ambrose who maintained he had left his recording device there by accident.
"That complaint was investigated with urgency by the police, search warrants were executed against various media outlets and considerable pressure was put on Mr Ambrose. He later apologised to the Prime Minister and John Banks before being given a warning by the police," Little said.
"This was a highly political complaint that looked more like damage-control of a public political stunt which the Prime Minister lost control of. It should never have been entertained by the police from the outset."
Little said the those charged with upholding the integrity of the electoral system needed to be willing to hold politicians to account when necessary and to prove they were independent of ministers.
A decision from Banks on his political future is expected tomorrow.
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