The true origin of the "mercury coherer with a telephone" receiver that was used by G. Marconi to receive the first transatlantic wireless signal on December 12, 1901, has been investigated and determined. Incontrovertible evidence is presented to show that this novel wireless detection device was invented by Sir J.C. Bose of Presidency College, Calcutta, India. His epoch making work was communicated by Lord Rayleigh, F.R.S., to the Royal Society London, U.K., on March 6, 1899, and read at the Royal Society Meeting of Great Britain on April 27, 1899. Soon after, it was published in the Proceedings of the Royal Society. Twenty-one months after that disclosure (in February 1901, as the records indicate), Lieutenant L. Solari of the Royal Italian Navy, a childhood friend of G. Marconi's, experimented with this detector device and presented a trivially modified version to Marconi, who then applied for a British patent on the device. Surrounded by a scandal, this detection device, actually a semiconductor diode, is known to the outside world as the "Italian Navy Coherer". This scandal, first brought to light by Prof. A. Banti of Italy, has been critically analyzed and expertly presented in a time sequence of events by British historian V.J. Phillips but without discovering the true origin of the novel detector. In this paper, the scandal is revisited and the mystery of the device's true origin is solved, thus correcting the century-old misinformation on an epoch-making chapter in the history of semiconductor devices.