Britain's Chancellor of the Exchequer is seen in a still image taken from video making a statement to the House of Commons about Barclays in Westminster, central London, June 28, 2012. Britain said on Thursday it had brought in the fraud squad to investigate possible crimes and would tighten laws over attempts to manipulate lending rates, a scandal which has engulfed Barclays and is expected to spread to other banks. Shares in Barclays tumbled as much as 18 percent at one point by midday trade, wiping out 4.2 billion pounds from its share price - the biggest one-day fall since 2009, according to Reuters data. Shares were down 14.8 percent at 1513 GMT.