Vegemite? not in america.

Mystified Australian authorities have launched an investigation into reports Vegemite has been banned from entering the United States.

Supermarkets in the US continue to stock Vegemite and have no plans to remove Australia's iconic breakfast spread from their shelves.

Adding to the confusion, a spokesperson from the Australian embassy in Washington DC said US officials had recently said they had no concerns about Vegemite.

Weekend media reports, however, described how US customs officers have been removing jars of Vegemite from travellers' bags as they entered America.

"We are aware of reports that US authorities have been seeking to stop people from bringing Vegemite into the country," a spokesperson from the Australian embassy in Washington DC told AAP.

"From our perspective there is no food safety issue with Vegemite and we had been advised recently by US authorities that Vegemite was not of concern to them.

"We are liaising with US authorities to determine whether the media reports are accurate."

The ban was reportedly due to Vegemite containing folate, which America's Food and Drug Administration only allows to be added to bread and cereals.

FDA officials did not return phone calls.

American supermarkets such as Bristol Farms and Whole Foods were selling Vegemite in their stores on Tuesday.

Nearly 100,000 Australians and New Zealanders live in the United States.

Vegemite is made in Australia by US-based Kraft Foods Inc.