Essex Police has launched a murder investigation after 39 dead bodies were found in a shipping container at the Waterglade Industrial Park in Grays, Essex.
Police have said early indications show there are 38 adults and one teenager.
The lorry is from Bulgaria and entered the UK from Holyhead in North Wales. Police have arrested a 25-year old man from Northern Ireland under the suspicion of murder.
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.”