She told the PA news agency: "A 32-year-old man has sadly died.

"At 10am today, the police received a signal to attend a man in a helpless condition, in the city centre.

"He was a foreign national, from Britain, and he was taken to hospital but he sadly died.

"Police are working to clarify all the circumstances in the incident.

"There is no further detail on any injuries.

"There will be a forensic examination to find out what the cause of death was."

A statement on the authority's website added that in hospital, the victim "suddenly began to act aggressively, raging and threatening".

A Foreign Office statement added: "We are supporting the family of a British man who died following an incident in Sofia, and our staff are in contact with the UK and Bulgarian authorities."

England supporters were involved in violent clashes with police in Prague on Friday, ahead of the Three Lions' 2-1 loss to the Czech Republic.

Asked about the trouble after the defeat, England manager Gareth Southgate said: "Of course, always disappointing and I think I've always spoken about how we would want everybody to conduct themselves."

The Foreign & Commonwealth Office earlier on Monday confirmed a British man was being supported following what is believed to be a separate incident in the Bulgarian capital.

Reports on Monday morning suggested an England fan had been taken to hospital after clashes ahead of the game.

An FCO spokesperson said in a statement obtained by the PA news agency: "Our staff are supporting a British man following an incident in Sofia and are in contact with the Bulgarian Police."