The health secretary has been urged to launch an urgent investigation into "truly shocking" reports that a cash-strapped health board used money from donations to fund a new technology.

NHS Tayside took more than £2m from its endowment fund - which is made up of donations from the public or bequests in wills - to cover general running costs, which could normally be funded from its core budget.

The health board, which was bailed out with a Scottish Government loan of £33.2m 2016-17, was reported to have used the endowment fund when "faced with a funding deficit" in 2013-14.

It was further claimed NHS Tayside had to temporarily suspend its constitution to allow this to happen, as the money was going to retrospectively fund projects already approved by the board.

Professor John Connell, chairman of NHS Tayside, said the projects that were funded "were appropriate for endowment funding".

But he said he wanted "further assurance" about the retrospective element of the decision-making process, adding that this would be included in "the planned externally-led review of NHS Tayside's financial governance announced last week".

Opposition politicians called on health secretary Shona Robison, who represents the Dundee City East area at Holyrood, to get involved.

Less than a week ago NHS chief executive Paul Gray told MSPs he expected NHS Tayside would require further brokerage cash from the government of between £9m and £12m.

Meanwhile, a review carried out by accountants Grant Thornton found that since 2012 the health board had "misrepresented" its financial performance by "holding" £5.3m that had been allocated by the Scottish Government for eHealth initiatives.