IPCC probe arrest of critically ill man in Essex
The arrest by Essex Police of a man who is now in a critical condition is to be investigated by a watchdog.
The 18-year-old had been pursued by officers and was arrested on Southend Arterial Road, near Romford, on 13 September.
He complained of severe abdominal pain 12 hours later, at Chelmsford Police Station, and was taken to hospital.
The Independent Police Complaints Commission (IPCC) said it would look at the circumstances.
It said the man was in intensive care, where his condition was described as critical but stable.
The man's sister made a complaint to the IPCC on 21 September.
The IPCC is analysing footage of the incident, working to trace independent witnesses to the arrest, and will be examining officers' initial statements, they said.
Anyone who witnessed the arrest, which took place at about 1500 BST at the Ardleigh Green Road junction, should contact the IPCC.