Alwaght- Emergency services have recovered 39 bodies from a container truck in south-eastern England, triggering the UK's biggest ever murder probes.
Chief Superintendent Andrew Mariner said on Wednesday that authorities were in the process of trying to identify the deceased; 38 adults and one teenager.
Police were alerted by the ambulance service shortly before 1:40am local time (00:40GMT) following the discovery of a truck container with people inside at the Waterglade Industrial Park.
Mariner said the truck entered the country on October 19 and that police were "working closely with our partners to investigate".
The 25-year-old driver, from Northern Ireland, was arrested on suspicion of murder, the police said.
UK Prime Minister Boris Johnson said he was "appalled by this tragic incident".
"I am receiving regular updates from the Home Office and will work closely with Essex Police as we establish exactly what has happened," he said. "My thoughts are with all those who lost their lives and their loved ones."