Embattled American insurance giant AIG, which is at the centre of a huge political row over bonuses, has paid out far more than previously thought to its executives, it was revealed yesterday.

In shelling out a reported $165m in bonuses to its top staff, AIG had already caused an almost unprecedented wave of anti-corporate anger in the US. The row has rocked President Barack Obama's administration and prompted new laws in a bid to try to claw back the money.

But now documents obtained by Richard Blumenthal, the attorney general of Connecticut, where AIG has offices, show the firm in fact has in fact paid out $218m in bonuses, 32% more than previously thought. The shocking news is certain to further inflame popular emotions against AIG, the financial sector as a whole and embattled Treasury Secretary Tim Geithner.

For many Americans AIG has become the unacceptable public face of the economic crisis. The AIG brand has in fact become so toxic that security guards have been placed outside the firm's offices and the homes of senior executives. Yesterday in Connecticut a group of protesters toured the state holding demonstrations outside houses owned by senior AIG management. They were hand-delivering a letter that asked for the executives to pay their bonuses back.

Many AIG executives have also faced death threats in the wake of bonus revelations as ordinary Americans, struggling in the face of the deepest economic crisis since the Depression, have wondered why financiers who helped cause the disaster should profit so much from it. An internal security memo issued last week by AIG warned its staff to travel in pairs in public, to avoid going out at night, to keep an eye out for unfamiliar faces near their work or homes and not to wear an AIG logo in public.

But the impact of the AIG scandal has gone far beyond the security fears of the firm's management. Though the actual amount of the AIG bonuses is relatively trivial compared to the more than $170bn the firm has received in bailout aid, and the several trillion dollars the government has flung at trying to end the recession, the saga has had a huge political impact.

The symbolism of the AIG bonuses has triggered an epic political battle in Washington, with some Republicans seeking to use the crisis to force Geithner to resign and to slam Obama. They have demanded to know when Geithner knew about the bonuses and why legislation that could have prevented them was removed at the apparent request of Treasury officials.

The furore has not left Obama unscathed. The normally slick message machine in the White House was stuttering all last week and left the president looking unusually beleaguered. "The administration has really had to scramble on this. It shows how angry and how politically dangerous the mood of the American public is right now," said Steve Mitchell, a political pollster and founder of Mitchell Research and Communications.

Though Obama remains essentially popular, the last week has seen a steady erosion of support for America's first ever black president. One study showed his approval rating dropping from 64% to 59%. Another revealed that the number of Americans who disapprove of Obama's performance had risen from 17% to 26%. "I don't think the honeymoon with Obama is over. But the public is spending a lot more time in the sun on the beach than in the hotel bedroom right now. He is slipping in the polls," said Mitchell.