It's been revealed that the United States and New Zealand conducted secret tests in the 1940s of a 'tsunami bomb' designed to inundate coastal cities. Thousands of underwater tests were carried out near Auckland during the Second World War and showed such a weapon was feasible. The top-secret operation code-named, ''Project Seal'', was shelved just months before the atomic bomb was used on Japan in 1945. The secret plans have been uncovered during research by a New Zealand author and filmmaker, Ray Waru. EMILY BOURKE: Where were these tests carried out? RAY WARU: They were carried out at one of ... New Zealand's most well-known holiday spots, the Whangaparaoa Peninsula just north of Auckland. Over a period of several months they carried out almost 4,000 test explosions to kind of calibrate the size of the explosions, the number of explosions and the depth of the explosion in the water would need to be in order to create a tsunami effect. EMILY BOURKE: Was there any damage that occurred as a result of the research and those tests? RAY WARU: No. They never actually produced a tidal wave. They decided at the end if there were 2 million kilograms and they were detonated in an array a specific number of kilometres from the shore that they would produce a wave ... about ten or 12 ... metres in height. That would have been enough to wash out a shore installation. EMILY BOURKE: Were these tests carried out at the behest of the United States? Did the United States fund it? RAY WARU: Yes they were [and] they were carried out with the full cooperation of the New Zealand government.