Exposure
In spite of numerous "successful" flights, every attempt to drill at the indicated locations came up empty. Bonassoli repeatedly stated that it appeared to be "too accurate" to be used and required further development. Their Elf contacts remained confident in the devices in spite of the failures, and would happily provide documentation of previous studies on the fields that were going to be flown over in the tests. These studies were then parroted back through the devices, further convincing the Elf managers that the devices worked.
Things started to change when management of Elf passed from Guillaumat to Albin Chalandon. Initially a supporter of the project, after examining project documentation, Chalandon was forced to admit that there was not a single usable result from the tests. In May 1979 he arranged for Jules Horowitz, chief of research and development for France's atomic energy agency, to visit the lab and examine "Omega". Instead of examining the device itself, he started asking Bonassoli questions about the Omega's capability to detect various common objects through a wall. After two failures, Bonassoli eventually agreed that it could easily detect a metal ruler. Bonassoli turned on the device, and sure enough out came a piece of paper with a short line on it. Horowitz returned from behind the wall and held up the ruler, which he had bent into a L shape while hidden from view.
Oddly, work continued. A month later another demonstration further revealed the hoax. Omega was shown to be outputting graphics projected from within the box. Further investigation showed that what was inside one cabinet did not simply appear to be a photocopier, but actually was a photocopier. This was the reason the devices' output always looked so similar to previous reports; Bonassoli was hand-copying them, and then simply pressed "copy" to generate output that looked similar, but slightly different, than the originals they had provided. Bonassoli attempted to deflect all criticism by stating that the entire secret of the device was one key component, which was locked in a box that he refused to open. But it was too late, Elf realized they had been hoodwinked.
Even after the hoax was discovered, the government did little to address the problem. Bonassoli managed to successfully return to Italy, where he became something of a folk hero. Elf never completed paying for the final contract, but nevertheless had spent over $150 million in total.
Read more about this topic: Great Oil Sniffer Hoax