The Scottish Cities Alliance (SCA), a Scottish Government-backed collaboration to win global investment to the country's seven cities, is refusing to say what funds it has won in the three years since its launch.

The SCA, administered by the public-private Scottish Council for Development and Industry (SCDI), has showcased Scottish projects with the potential for investment, including the Dundee Waterfront and Glasgow's City Science project, at commercial property trade fairs in Scotland, London and Cannes in France.

But repeated requests from the Sunday Herald for an update on the amount of inward investment the alliance has raised have been stonewalled, prompting a request for the information under freedom of information legislation.

One of Scotland's most senior commercial property experts, Peter Muir, Glasgow-based director of the commercial real estate company Colliers International, said: "If the SCA is receiving public funding I think they should by now be ­providing some facts and figures.

"Any project that will help to deliver regeneration and investment is to be welcomed, and three years is enough time for the project to have bedded down and to have borne some fruit. It is disappointing that they are not prepared to release that information."

Gavin Brown MSP, Scottish Conservative finance spokesman, said the SCA ought now to be in a position to reveal a total figure of investment secured. He said: "I accept that there might be various commercial sensitivities [about releasing information on specific projects]. However, at the aggregate level they must be able to tell us something."

He added: "The SCA principle is a good one: that the seven cities would work together as one team. But we have seen a lack of activity particularly from [Cities Minister] Nicola Sturgeon who personally has not driven it in a way that it should be driven.

"There are no doubt investments going on, but are any of these investments that would have happened anyway without the alliance? The question is: what has been the added value?"

James Kelly MSP, Labour's spokesman for cities, said: "It is difficult to see that the group has produced anything that is going to deliver tangible benefits.

"If you look at some of the English cities, they are already on to the second edition of the City Deal. We need to balance power between Holyrood and the cities, and get a strategy that delivers economic growth, connectivity and proper jobs."

The £7 million Scottish Cities Alliance was established in December 2011 as a partnership between the Scottish Government and the cities of Aberdeen, Dundee, Edinburgh, Glasgow, Inverness, Perth and Stirling. Its stated aim was to maximise investment, stimulate economic ­activity and create jobs.

Last month, the alliance produced its first investment prospectus: a lavishly illustrated 36-page booklet detailing £10 billion worth of investment opportunities. This came ahead of the MIPIM investment fair in London, billed as the ultimate ­"property marketplace" and attended by council officials from the seven cities.

An official from Edinburgh City Council told the Sunday Herald that as a result of visiting the SCA stand at the MIPIM event, one potential investor had arranged to visit Edinburgh with a view to investing in a property scheme. But he declined to give more details.

And SCA policy executive Iain McCreaddie said: "They [the SCA's investment team] feel they have answered the questions … We don't really have anything more to say."

Some 14 officials from SCA local authorities attended the three-day MIPIM fair in Cannes in March this year at a cost of £277,000.

In January, the SCA appointed a new chief executive, Stewart Carruth, currently deputy chief executive of Stirling Council. His appointment was presented as a sign that the project was moving into "the delivery phase" after two years of "framework building".

The Sunday Herald this week tried to speak to the SCA to gain more detail, without success. As these pages went to press, Carruth contacted the newspaper to offer an interview at a later date.