A series of unusual burglaries, reports of spies looking for listening devices and claims of car tampering have prompted alarmed experts around the world to call the New Zealand's government to protect a vocal China critic.
University of Canterbury professor Anne-Marie Brady says she has been victim of attempts to silence her since the publication of her major report criticising China's alleged influence in New Zealand last year.
In February, she told an Australian parliamentary committee her office and home had been burgled, noting laptops had been taken but other valuables left untouched.
New Zealand police in September confirmed there was an ongoing, unusually long and well-resourced probe into the break-ins, with Interpol called in, and the NZ Herald reported spies had been called to search Prof Brady's office.
Now, in an open letter, 164 academics, former diplomats and journalists from around the world, including Australia, have called on the New Zealand government to give Brady police protection, saying authorities have been too slow to act.
"The harassment campaign against Brady risks having a chilling effect on scholarly inquiry, allowing the CCP to interfere in the politics of our societies unfettered by informed scrutiny," it says.
"We urge the New Zealand authorities grant Professor Brady the necessary protection to allow her to continue her research, sending a clear signal to fellow researchers that independent inquiry can be protected."
The letters comes after dozens of academics and human rights advocates in New Zealand called for the government to treat the claims more seriously.
Prime Minister Jacinda Ardern told reporters last month she would respond if conclusive evidence was obtained.
"If I received a direct report that said there was an issue there that could be directly attributable to China, or at China's direction, we would act on that. But I have not received such information," she said.
The National Party and Labour have played down suggestions of political interference by China, saying the country's donation and electoral system are up to scratch and authorities are vigilant.
A report by the Hoover Institution, a conservative American think tank, recently described New Zealand as particularly vulnerable to China's influence and criticised a lack of government action when compared with Australia.