The Independent Office for Police Conduct is investigating the death of a man who had been held in custody at Walworth police station, the London Met has confirmed.
Police said the 26-year-old driver was stopped on Brandon Street, SE17, at approximately 11.30 am on Friday, March 30 and detained on suspicion of possessing a knife.
After a lock knife was found in the vehicle he was taken to Walworth police station where, at 12.15 pm, custody staff called an ambulance after suspecting he had swallowed a substance.
The man was taken to a central London hospital by ambulance and died on Saturday, March 31.
A post-mortem will also be held.
Police have confirmed that the London Met’s Directorate of Professional Standards is investigating and a referral was made to the Independent Office for Police Conduct (IOPC), which has begun an independent investigation.
IOPC regional director, Sarah Green, said: “My thoughts are with the young man’s family and friends at this most difficult time, as well as all those affected by this tragic incident.
“We were made aware of the man’s arrest, and that he had been taken to hospital, on the afternoon of Friday, March 30 and we sent our investigators to the custody suite and to post incident procedures.
“They have been working since that time to gather all the available evidence at this early stage of our investigation.
“We will be offering the man’s family regular updates on the progress of our investigation.”