Essex Police said they were called at around 1:40 a.m. on Wednesday to the Waterglade Industrial Park, Grays, around 20 miles east of central London, to reports of a truck full of people.
When emergency services arrived on the scene, all 39 people inside were pronounced dead. At this stage, it is believed the victims are 38 adults and one teenager. The truck is also believed to have come from Bulgaria.
Police said a 25-year-old-man from Northern Ireland has been arrested on suspicion of murder.
Essex Police Chief Superintendent Andrew Mariner said: “This is a tragic incident where a large number of people have lost their lives. Our enquiries are ongoing to establish what has happened.
“We are in the process of identifying the victims, however I anticipate that this could be a lengthy process.
“We believe the lorry is from Bulgaria and entered the country at Holyhead on Saturday 19 October and we are working closely with our partners to investigate. “We have arrested the lorry driver in connection with the incident who remains in police custody as our enquiries continue.
“I appreciate this cordon is going to disrupt the activity of local businesses in the area and we will work to ensure that disruption is kept as short as possible.
“We are working with Thurrock Council to mitigate against any impact our investigation scene will have locally.”
Police said a cordon has been put in place and access to and from the Waterglade Industrial Park is currently restricted.
Following the discovery, Britain’s Prime Minister Boris Johnson said: “I’m appalled by this tragic incident in Essex.
“I am receiving regular updates from the Home Office and will work closely with Essex Police as we establish exactly what has happened. My thoughts are with all those who lost their lives & their loved ones.”
Jackie Doyle-Price, a Conservative MP whose constituency of Thurrock is located where the bodies were found, tweeted: “Sickening news of 39 people found dead in a container in Grays. People trafficking is a vile and dangerous business. This is a big investigation for Essex Police Lets hope they bring these murderers to justice.”
Britain’s Home Secretary Priti Patel added: “Shocked and saddened by this utterly tragic incident in Grays. Essex Police has arrested an individual and we must give them the space to conduct their investigations.”
