It's more than a decade since Evander Holyfield was one of the most well known athletes on the planet as the owner of the undisputed world heavyweight boxing championship.

But a comical sign of how far the 49-year-old boxer has faded from view occurred on U.S. television when broadcaster NBC interviewed him in London without appearing to realize who he was.

Holyfield was interviewed in a vox-pop montage of tourists in London aired on NBC's Today Show morning program.

"The today show did interview me yesterday and ur right they didn't mention who I was," a bemused Holyfield admitted on Twitter.

Holyfield won a boxing bronze medal at the 1984 Los Angeles Games before embarking on a successful professional career best remembered for his two epic fights with Mike Tyson in 1996 and 1997.