The Kent Messenger Group has revealed the background to why plans for a multi-million pound arts centre off the coast were scrapped after costs spiralled to nearly £40m.

A request made under the Freedom of Information Act by group political editor Paul Francis has led to the publication by Kent County Council of an eight-page report detailing what went wrong with the Turner Centre, an ambitious arts gallery that had attracted national publicity and was hailed as an iconic design.

The flagship project was to be built partly in the sea bed off Margate Pier but was abandoned in February after the county council said it could not afford the projected £39m the centre was expected to cost – double the original estimate.

At the time, county councillors refused to go into detail about what had gone wrong with the scheme, saying only that 11th-hour changes to the design had nearly doubled the amount they had intended to spend.

And it blocked Paul’s initial request for more information, saying the release of “raw data” relevant to what went wrong could result in a “public debate that might also be aired in the media”.

That refusal has been referred to the Information Commissioner, but in the meantime, the release of an independent consultant’s report, commissioned by the council, has revealed that the arts centre was at risk of being swept away in a freak storm.

As a result, Edmund Nuttall Ltd, the construction company leading the project said an additional 1,200 tonnes of steel would be needed.

The report catalogued a series of other problems and difficulties and hints at wrangles over the design but omitted to say how much county councillors knew.

Paul said: “This was a project that Kent County Council spent at least £7m of taxpayers’ money on, so it was evidently in the public interest that more was revealed about what went wrong.

“There remain a lot of unanswered questions and we are still waiting for a ruling from the Information Commissioner which could generate more details.”