Police cordoned off a central London street after a man collapsed and died amid fears he had been poisoned.
Emergency services closed Albemarle Street in Mayfair during a major response to the incident on Thursday afternoon.
The man fell ill in the street just before 3.15pm and specialist police responded “to concerns the victim may have been exposed to a poison”.
The victim was pronounced dead at the scene by paramedics, but police said there was no indication of foul play.
A Scotland Yard spokesman said: “Police responded to a call from the London Ambulance Service (LAS) relating to a man taken ill on Albemarle Street in Mayfair.
“Officers attended the scene. At the location they found a man being treated by the LAS. He was subsequently pronounced dead at the scene.
“Due to concerns the victim may have been exposed to a poison, specialist officers attended but found no evidence that would indicate the victim had been poisoned.
“There are no other reports of people being taken ill.”
Pictures of the scene showed several ambulances, a heavy police presence and what appears to be a body bag in the West End street.
Police later erected a forensics tent in the road, which is lined with high-end shops and restaurants and close to foreign diplomatic buildings.
Dave Mutton, who works at the Royal Institution building in Albermarle Street, said staff were told by police to remain indoors.
He told The Independent: “We saw lots of ambulances and police outside and sirens.
“I went down to the ground floor just out of curiosity and poked by head out. There were a lot of police and ambulances around. Police were taking statements from people and said basically go back inside.
“A bit later on it all seemed to be calming down... and they had a much smaller police cordon. There was an ambulance in the middle of the road and there seemed to be something in the road.”
A coroner's ambulance later arrived at the scene.
A London Ambulance Service spokeswoman said: “We were called at 3.14pm today to Albemarle Street, Mayfair, to reports of a person in cardiac arrest.
“We sent a number of resources to the scene, with the first of our medics arriving in five minutes.
“Sadly, despite our efforts, a man died at the scene.”
