A teenager died after a night partying at a nightclub where Wayne Rooney had been celebrating being named Player of the Year.
The 17-year-old collapsed at London's Whisky Mist - a celebrity haunt frequented by young royals - at approximately 1.20am.
He was taken to a central London hospital by ambulance where he was pronounced dead, police said.
A 37-year-old man was later arrested on suspicion of supplying class A drugs.
He is being held at a central London police station.
A Scotland Yard spokesman said: "We can confirm that we were called at 1.20am to reports of a man collapsed at a venue in Hertford Street, W1.
"An ambulance attended and the 17-year-old was taken to a central London hospital where he died a short while later."
A post-mortem examination will be held. Officers from Westminster are dealing with the incident.
Rooney, who was pictured leaving the Mayfair venue, had been at the club with fellow England footballer Ashley Cole.
Earlier that evening he landed the Professional Footballers' Association (PFA) Player of the Year award.
He was chosen ahead of fellow nominees Cesc Fabregas, Carlos Tevez and Didier Drogba for the prestigious PFA award, ensuring a fourth successive win for Manchester United.
The club's former shareholder, Guy Pelly, today expressed his sadness about the teenager's death.
"I was extremely sorry to hear about the tragic incident on Sunday but I am unable to comment further," he said.
"As of a couple of months ago, I am no longer a shareholder of the nightclub Whisky Mist."
A spokesman for Cole said the first he knew about the events of last night was as he left the club.
He said the footballer did not know the person involved.
The spokesman said: "Ashley was unaware of the unfortunate situation and only became aware of it as he left the club.
"He couldn't assist in any way with the inquiry because he didn't see anything or know anything about the incident."Reuse content