Hedge funds have doubled their negative bets on carmaker Volkswagen less than a year after a sudden 82% share price rise triggered €30bn ($38bn) of losses for firms that had shorted its stock - a trade which one investor dubbed "a real car crash".

Since the middle of July, hedge funds have almost doubled their bets that Volkswagen shares will fall, according to short selling analysts Dataexplorers. Almost a third of the company's ordinary shares available for borrowing are now out on loan.