US talk show host Stephen Colbert has come under fire over his recent remarks on the royal photoshop scandal.

During an episode on The Late Show, Mr Colbert rehashed rumours of Prince William's alleged affair with Rose Hanbury amid continued speculation surrounding Kate Middleton's health and her whereabouts.

Sky News contributor Prue MacSween weighed in on Mr Colbert's take on Princess Kate's Photoshop fiasco.

“The fact that they're dragging up a supposed affair is really just trying to give this story some more air.

“I just find it pathetically sad that they're doing it, but the Palace has clearly got to do something about clearing up making.

"Let's not scrape the bottom of the barrel with all of these theories."