In the US the relentless drive against corporate corruption gathers pace, with former ImClone chief executive Sam Waksal pleading guilty on insider trading charges. This move could drag his close friend, the home making icon Martha Stewart, into the web. Citigroup, the world's biggest bank, has new difficulties with allegations that its Travelers insurance offshoot made 'secret loans' of £438m ($679m) to Bernie Ebbers, disgraced former chief executive of WorldCom.