Feinstein, the director of Feinstein Doak, tracks North Korea's online media for NK News - a United States website - from a "poky wee conservatory" in his Redcliffs flat in New Zealand. NK News says KCNA - or the Korea Central News Agency - has deleted more than 35,000 articles, including those mentioning executed former top government and party official Jang Song-thaek, from its online archives. Feinstein's discovery means that, with the exception of a small number of articles about Kim Jong-un, the digital record of state-approved news stops at October 2013. In addition to the 35,000 original Korean language articles, deleted from KCNA, translations in English, Spanish, Chinese and Japanese were also removed. Feinstein also discovered 20,000 articles were removed from the archives of the Rodong Sinmun - a state newspaper.

"This is a calculated thing they have done and the order most likely came from above each individual agency. It is a true North Korean purge, not just a KCNA one," he says. Feinstein was educated at the Christchurch Rudolf Steiner School, which was "never too hot on computers". But as a result, he says, he thinks "outside the box". He travelled in his 20s, visiting China and Eastern Europe. His Lithuanian ex-wife grew up under Soviet communism and her country's history fascinated him. People think one thing in private and say other things in public. All of that fascinates me. "I got really interested in reading her old textbooks. I am very cynical about propaganda but it was more sophisticated than what I thought it would be.

"People think one thing in private and say other things in public. All of that fascinates me - how governments treat their citizens," he says. Feinstein returned to Christchurch in 2009, KCNA Watch went live in April this year and Washington-based NK News contacted him to strike a deal soon after. They employ his watchdog services, by leasing KCNA Watch - a "sophisticated" programme, on a monthly basis. "[KCNA Watch] grabs everything North Korea puts out and will immediately tweet about it . . . and categorise articles according to people, countries, topics. You have to really understand how their systems work. "They frequently ban every IP address in New Zealand to stop me. To stop that I use an army of secondary servers all over the world," he says. Feinstein says the word "hacker" doesn't sit comfortably with him, because it means one thing to tech-folk and something different in popular culture.

"In the tech world it is just like customising your car a little bit - maybe putting mag wheels on it. There is no implicit criminality about the word. You can either hack criminally or you can not. That is a choice," he says. He concedes the work he does for KCNA Watch and NK News "is absolutely against the law" in North Korea but he is not worried. Big Brother is coming for you is "a running gag", but "the reality is . . . for anything to happen to me in this country . . . it would be an international problem". Fairfax NZ News