Barack Obama, the presumptive Democratic nominee for president, has set up a website that aims to counter political smear tactics.

Fightthesmears.com was launched to counter an increasing number of false stories about the presidential candidate.

These include the suggestion that his wife Michelle used the term 'whitey' in a speech, and that Obama himself is a Muslim, which 11 per cent of Americans in a recent poll believe to be true.

"We will not allow Michelle or, for that matter, Barack to be defined by rumours," Obama adviser Anita Dunn told Time magazine.

Obama's campaign team is now actively recruiting support to seek out such rumours so that they can be officially debunked on the site.

Fightthesmears.com includes an automated mailing system so that the correct information can be sent on to others.

The idea came after the increasing use of the internet to spread rumours about political figures, including Obama.