Image copyright Getty Images Image caption Prince Charles and his wife Camilla were tested for coronavirus by NHS Grampian

There were "very good reasons" to test Prince Charles for coronavirus, Scotland's chief medical officer has insisted.

The heir to the throne is currently in isolation in Aberdeenshire after testing positive for Covid-19.

Questions have been raised over why he was eligible for a test from NHS Grampian while many frontline medical workers have been unable to get them.

Catherine Calderwood said the prince had been tested for "clinical reasons".

Clarence House announced on Wednesday that the Prince of Wales - who is known as the Duke of Rothesay in Scotland - had tested positive for the virus.

A spokesman said the 71-year-old prince had "mild symptoms" but was in good health and spirits, and was working from home from his residence at Birkhall, on the Balmoral estate.

Image copyright Getty Images Image caption Catherine Calderwood said she had spoken to NHS Grampian staff who looked after the Prince

His wife Camilla, 72, was also tested for the virus, but the result was negative.

Clarence House said the couple "met the criteria required for testing", but the NHS Scotland website states that "generally" people are only tested if they have "a serious illness that requires admission to hospital".

SNP MSP Joan McAlpine wished Prince Charles a speedy recovery, but added: "Given that his symptoms are said to be mild, like many I wonder how he was tested when many NHS and social care workers cannot get tested."

Ms Calderwood defended the decision during an interview with the BBC's Good Morning Scotland programme.

She said: "I have spoken to the team in Grampian who were looking after the individual.

"My understanding is there were very good reasons for that person and his wife to be tested, and obviously I wouldn't be able to disclose anything else that I know because of patient confidentiality."

BBC Scotland has spoken to a woman living in the same household as a frontline clinician at NHS Grampian. Both are isolating because she has been displaying symptoms - meaning the clinician is unable to go to work.

But they do not know whether they actually have coronavirus because they have not been able to have a test.

The woman said she knew of "several other members of staff" who were also in isolation for 14 days but had not be able to access any testing from NHS Grampian.

She said: "We can't have a situation where staff are at home for 14 days in isolation and they may be negative. We need to get people tested so that if they are negative, they all need to get back to the front line where they are required.

"I think it's shocking that NHS Grampian have been able to go out to Balmoral and test not only Prince Charles but Camilla, who is asymptomatic, when we have frontline medical, nursing and other key worker staff at home who are unable to access testing."

An NHS spokesperson said testing for key staff was "being rolled out now".

They said: "Symptomatic household members who live with a critical member of staff will be offered testing for Covid-19 and influenza to inform a decision about lifting household isolation and allowing the critical staff member to return to work.

"We appreciate this process has taken longer to put into practice than we would have liked, but it needed to be absolutely fit for widespread demand and risk prioritised."

Questions have also been raised about why the Prince was allowed to travel to Scotland after he had started to show mild symptoms.

People have been urged not to use second homes or holiday lets in remote parts of Scotland for self-isolation, as this can add extra pressure to local health services.

First Minister Nicola Sturgeon said she did not want to comment on the specific case of the Prince, but added: "We want people to behave responsibly, we don't want people to see the Highlands and islands of our country as places where they can outrun the virus.

"Obviously there are places where people have homes in Scotland and people will choose to go to their homes, but we should all be responsible."