UNITED Nations investigators are to "call in" controversial plans for a £300m hotel, shops and housing complex at the heart of Edinburgh's World Heritage Site.

Fresh fears over the potential impact on the capital's site status were raised after the Caltongate plan, shelved after a previous developer Mountgrange folded, was resurrected in December.

Now the new interpretation of the original plan is to be scrutinised after a South African-led consortium took over the proposals.

Heritage bodies will examine details Artisan Real Estate Investors' new plans ahead of submitting separate objections. But The Herald understands the two main watchdogs, the Cockburn Association and Edinburgh World Heritage are to meet this week on the issue.

Despite earlier compromises, concerns remain over the demolition of the Canongate School despite studies ongoing into keeping the building as a community hub.

Euan Leitch, vice-chairman of the Scottish Architectural Heritage Society, is advising the association. He said: "I would argue redevelopment of the site does not require the demolition of the school."