A 72-year-old woman who suffered serious burns in a fire in a garden believed to have been started deliberately has died.
She was airlifted to hospital after a "disturbance" in Benfleet, Essex, on 13 March but died on Friday.
Police believe it was a "deliberate act" and arrested Kieren Lynch on suspicion of attempted murder.
The 50-year-old died from burns a day after the fire. Police are not looking for anyone else.
The Independent Office for Police Conduct has confirmed it is investigating prior police contact with the man, from Canvey Island.