Police investigating burglaries of China researcher Anne-Marie Brady obtained evidence believed linked to the culprits, but the national security case remains stalled awaiting a "forensic hit".
The case of a cluster of burglaries of Brady's home and University of Canterbury office was last February formally classed as "unresolved" following a year-long investigation involving NZSIS and Interpol.
Brady had shot to national and international prominence in 2017 with the publication of her 'Magic Weapons' paper outlining China's influence campaign - conducted largely through front NGOs, political donations and board appointments - in New Zealand.
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The burglary of her home in February 2018 - where only dated electronic devices used in her research were stolen - came the morning before her testimony to an Australian parliamentary committee considering laws curbing foreign interference. Her office was broken into 24 hours later.
Documents released by police to the Weekend Herald under the official information act show the investigation is presently stuck in limbo, with the officer in charge initially seeking to redact material to referring to the forensic evidence and expressing hopes it might provide a future break in the case.
"The file is not closed, as there are current forensic matters that remain alive but are unable to be further advanced at this time. This is a very real prospect that this could change if a forensic 'hit' occurs," Detective Inspector Stu Allsopp-Smith told colleagues in an email in March last year.
Brady said the case stalling was frustrating, but expressed confidence in the police investigation.
"I was in shock, as you usually are after these things. I didn't feel my emotions for a while, but anyone that has had their home of office burgled has a sense of violation and loss of safety," she said.
"I have been kept regularly informed as the months have gone by - and really thorough work has been done. They've wanted to assure me that I'm safe in my own home, and I appreciate that. "I just want to them work out what's behind all this.""
Brady and police declined to answer questions about the nature of the forensic evidence gathered.
A letter prepared last year to update Brady was eventually released unredacted to the Weekend Herald, confirming the half-break in the case: "Police retain some forensic samples that may lead to an identification in the future."
The letter also said evidence was found that the filing cabinet in her office had been jemmied open: "A filing cabinet lock was forensically examined by the ESR. This revealed marks inside the lock that may relate to it having been opened with a key or similar."
The letter and files reveal a depth of investigation far beyond those undertaken for typical burglaries, with CCTV footage of the area around her home reviewed and her entire street door knocked. It is understood several nearby burglaries were solved as a result of the inquiry, but with the offending and offenders later determined to be unrelated to the Brady case.
Complaints from Brady about her car being sabotaged triggered another, similarly unresolved, investigation: "Evidentially the experts were not able to say, with any certainty, that your two left tyres had been interfered with."
The case is being overseen by Allsopp-Smith, described as the manager of the national security investigations team. This unit of police is typically tasked with counterterrorism cases.
Requests to interview Allsopp-Smith about the case this week were declined by police. In a written statement a spokesperson said their investigation was "lengthy and detailed" and "remains open and is unresolved at this time".