New Zealand scientists involved in the building of the atomic bomb during the Second World War were investigated during a British probe into Soviet espionage.
The scientists included the Nobel Laureate Professor Maurice Wilkins.
According to secret Whitehall files just made public, all Australian and New Zealand scientists who worked on the joint US-British Manhattan Project to make the A-bomb came under suspicion.
One unnamed scientist was said to have passed on everything he knew about the programme.
In response, British spy agency MI5 investigated all the scientists involved in the project, including Professor Wilkins.
However the agency concluded there was no evidence against him and the investigation was dropped.