"We know that different organisations compile information of this nature from publicly accessible sources for a range of purposes, ranging from private companies wanting to carry out marketing or research at one end of the spectrum, through to governments seeking to influence public discussion or gather intelligence in other countries at the other."
Kitteridge said she understood that some people might've been unaware that information could be gathered up in this way, but it served as a warning.
"This is a timely reminder to everyone to check the security settings on their social media accounts and review the amount of information they are sharing on the internet," she said.
The SIS had the information relating to New Zealand, and would review it "for any potential risks and security concerns," Kitteridge said.
New Zealanders form a small part of the dataset, which is said to contain personal details of 2.5 million people around the world, including politicians, their family members, judges, business people, journalists and criminals.
The information was initially leaked from Zhenhua Data, a company based in the southern China city of Shenzhen, to American academic Christopher Balding.
More than 250,000 listings in the company's 2.4 million-strong Overseas Key Information Database (OKIDB) — apparently built with open-source information — were leaked to Balding, who had worked in China until 2018, and extracted by Australian cybersecurity expert Rob Potter.
The listings include town of residence, links to social-media accounts and notes indicating a particular interest in job titles or criminal convictions for tax or trafficking offences.
The leaked information was provided to a consortium of international journalists, and the findings have caused a storm of controversy in Australia, the US and the United Kingdom.
The Deputy Prime Minister earlier warned that "malicious actors" were exploiting Kiwis' private information after his daughter was targeted and tracked by a firm with ties to China's military.
The families of Winston Peters and other senior politicians — including Prime Minister Jacinda Ardern — have also been in the Chinese big data company's sights.
The sister and parents of Ardern have had profiles built on the secret Chinese database, along with the mother of former trade minister Todd McClay and one of ex-prime minister Sir John Key's children.
University of Canterbury professor Anne-Marie Brady, a specialist in China, said the revelations showed a concerted influence campaign from China targeted at political and business elites.
"Our New Zealand politicians are being targeted on a grand scale, and in minutiae,'' she said.
The Herald has obtained the New Zealand entries in the leak and is working through the nearly 800 listings to determine their significance.
Patterns seen in overseas analysis of the OKIDB leaks as a map of networks of interest — capturing influential figures in politics, business, technology, the judiciary, military and race relations, and their immediate family members — are reflected in the New Zealand listings.
Particular interest seems to have been paid to prominent executives in telecommunications, biotechnology and venture capital firms, along with foreign-affairs diplomatic staff focused on China.
