New details over concerns about Edinburgh’s world heritage status have been revealed.

Several controversial developments in the city have been described as "deeply worrying" after attracting the attention of world heritage inspectors

Hotel plans for the old Royal High School site at Calton Hill and St James Centre's £850m development have prompted fears Edinburgh could lose its Unesco World Heritage Site Status.

The city’s old and new towns have held the status since 1995 and are among just six world heritage sites in Scotland.

The UK branch of the International Council on Monuments and Sites (ICOMOS), which gives advice to Unesco on world heritage sites, visited Edinburgh in October last year.

Now their findings have been revealed in a report to be discussed by the city council’s planning committee on Thursday.

ICOMOS highlighted three key issues - the impact of "unsympathetic" developments, the effect on the "visual integrity" of the city and a "weak" planning process which does not focus enough on heritage values.

The concerns were raised in a letter written from the World Heritage Centre to the Department of Culture, Media and Sport. The department had earlier outlined seven developments, including the Royal High and St James Quarter projects, that were likely to affect the "outstanding universal value" of Edinburgh's old and new towns.

World Heritage director Mechtild Rossler wrote: "The quality and pervasiveness of development projects that are being pursued without consideration for conservation of the property is deeply worrying."

Alison Johnstone, Scottish Green MSP for Lothian, said the report was a "wake-up call" for local and national government.

She said: "We have a developer-led system that leaves our fantastic built heritage vulnerable to inappropriate development.

"There is a balance to be struck to ensure Edinburgh is a city that works for local people but also continues to draw visitors from around the world."

Planning convener for Edinburgh City Council Ian Perry said it was "immensely proud" of its Unesco world heritage status and took the management role of it "very seriously".

"Our current five-year world heritage management plan comes to an end this year and, as such, we are working closely with our partners Historic Environment Scotland and Edinburgh World Heritage on the next plan, which will see us through to 2021," he said.

"This will be informed by input from key stakeholders, including ICOMOS-UK and other heritage bodies, within the context of the city’s local development plan and national planning legislation in order to maintain what Unesco has classed as an area of outstanding universal value."

Susan Denyer, of ICOMOS-UK, said: "The revision of Edinburgh’s world heritage management plan is an opportunity to set out a strengthened and consolidated vision for a ‘living city’ as well as to foster partnerships and define strategic guidance to ensure development brings social and cultural as well as economic benefits. ICOMOS-UK welcomes the opportunity for engagement with this process.”