The origin of the term "Bombay duck" is uncertain. Some authors advance the theory that, during the British Raj, the fish was often transported by rail after drying. The story goes that the train compartments of the Bombay Dak (in English, the Bombay Mail) would smell of the fish, consequently leading the British to euphemistically refer to the peculiar smell as the "Bombay Dak". A variant of the story is that, though the fish weren't transported on the train, it smelt strongly because of the rotting railway sleepers over which it travelled, and this was thought to resemble the smell of the drying fish. In either case, this was supposedly corrupted into "Bombay duck". Although the likelihood of this origin is questionable, it does have the authority of a BBC Radio 4 interview in August 2006.