Canterbury University professor Anne-Marie Brady suffered a number of suspicious burglaries in early 2018 that she - and other scholars and intelligence analysts - have said were likely a response to her critical work investigating China's foreign influence activities.
The investigation, which stretched for almost a year, involved the police's secretive National Security Investigation Team, international law-enforcement body Interpol and spy agency the New Zealand Security and Intelligence Service. The latter agency also swept Brady's home and university office for bugs.
In a statement today police said they had been unable to resolve the case.
"Police have taken these incidents very seriously and a lengthy, detailed and extensive investigation has been conducted. This has involved all necessary police resources including detailed forensic analysis, interviews and expert advice."
"The burglaries and other matters reported remain unresolved at this time. The investigation is now at a point where there are no further lines of inquiry to pursue unless new information becomes available."
Brady told the New Zealand Herald she had been informed of the investigation's conclusion on Monday, and was disappointed with the result
"I am disappointed that despite the hard work of individual officers the police have not identified the culprit," she said.
Brady, an internationally respected academic, emerged as a public figure in late 2017 after publishing her Magic Weapons paper using New Zealand as a case study in mapping out China's international influence campaigns.
Brady's work focused political donations, board appointments for ex-politicians and their families, and connections between these and China's external influence agency the United Front Works Department. Following publication Brady has travelled to brief officials in Ottawa, Washington, London, Canberra and elsewhere.
The burglary of her home on February 14 saw devices - laptops and a burner phone - used to research the paper taken, but other valuables - including jewellery and cash left in the open - ignored. The following day, her office was also broken into.
In November her mechanic, unaware of the ongoing probe into the case, reported he believed her family's car had been "tampered with" after finding both front tyres had dangerously low pressure. Police folded this claim into their investigation.
Early on, Brady had classed the burglaries as harassment in response to her work on China. Days after the burglaries she told an Australian parliamentary committee her earlier research on Antarctic politics had seen pressure put on her employer, and more recently people she associated with in China had been questioned by Ministry of State Security officials.
Today's developments comes as relations between China and developed nations, particularly the United States, have become increasingly fractious as disputes over trade, claimed security risks with telecommunications firm Huawei, and China's apparent retaliatory detention of foreign nations are boiling over.
The New Zealand government has long-sought to put the case of the burgled professor to one side, consistently declining to comment citing the ongoing police investigation.
With the investigation now concluded, all eyes turn to the Beehive to see if the government has reached conclusions of its own about the affair and how they will be managed in light of an increasingly rocky relationship with Beijing.
The episode has been closely-watched internationally, with the likes of the New York Times, Guardian, Sunday Times and South China Morning Post covering the case and more than 300 international China-watchers signing an open letter in December saying they were "alarmed and appalled by the recent wave of intimidation directed against our colleague".
