RUMOURS about European firms paying huge bribes to politicians and other intermediaries to smoothensales of their products surface periodically, but more often than not they peter out for lack of hard evidence. But while the ongoing bribery scandal in Canada involving a European company (Airbus Industrie) and politicians (notably former prime minister Brian Mulroney), too, might eventually end in a scurrilous whimper, for the moment there are enough intriguing and murky clues to power a hard-headed investigation.