The 38-year-old, who had a young son, died in hospital on Saturday – two days after laboratory tests confirmed he had the disease.

He returned to the UK from Afghanistan on Tuesday, via a connecting flight from Dubai.

His friend Mohammed Asif said he was an Afghan national who came to Britain seeking asylum several years ago and lived with his wife and young son, aged around five or six, in Glasgow, where he owned a garage in the East End.

Mr Asif said the man had been in Afghanistan to attend his brother's wedding in Samangan Province.

Concerns have now been raised about three of his family members in the village of Aibak, Afghanistan, who are said to be displaying symptoms of the fever.

Mr Asif, acting chairman of the Scottish Afghan Society, of which the man was a member, said: "I spoke with friends over there about two hours ago, one of his brothers is having the same problems he did – vomiting, body aches and pains in his ear.

"Two women from the family also have some symptoms."

The man was picked up from Glasgow Airport on Tuesday by a friend, and within three hours was admitted to hospital.

He was initially treated in isolation at Gart-navel General Hospital's Brownlee Centre, which specialises in infectious disease, before being flown from Scotland to a high-security infectious disease unit at London's Royal Free Hospital.

NHS Greater Glasgow and Clyde said it has identified and contacted four passengers who may have had contact with the patient on the Emirates flight from Dubai to Glasgow.

The health board said two of them – one who remained in "close proximity" to the ill man during the flight – will be monitored on a daily basis for the next two weeks.

The other two passengers do not require follow-up surveillance and the risk to all other passengers on the flight and the general public is "extremely low".

The Health Protection Agency said it was the first laboratory-confirmed case of CCHF in the UK.