The former model began a romance with Middleton in February, 2013 but they have now decided to call time on their relationship, according to editors at British newspaper The Sun.
A source tells the publication, "The split happened a couple of weeks ago and it was James' decision. He just didn't think it was going to go the distance."
In a post on Instagram.com on Wednesday (23Sep15), former The Big Breakfast host Air apparently hinted at the split by posting an image of a chalk board emblazoned with the message: "Accept what is, let go of what was, have faith in what will be."
Air has previously told how the couple tried to remain out of the spotlight, saying, "I don't feel like it is high-profile because James and I don't court publicity. We don't have a big showbiz celebrity life in any sense."