One person has been hospitalised after being found in the back of a lorry near the Dartford Crossing in Kent, along with 12 other people.
A South East Coast Ambulance Service spokeswoman said the person taken to hospital was not believed to be in a life-threatening condition.
They said: "Our crews assessed 13 individuals at the scene. One required transportation to hospital and they were taken to the Darent Valley Hospital. "They didn't appear to be in a life-threatening condition. The other 12 were taken to Dover."
Kent Police confirmed they were called to a report of suspected illegal immigrants but said that the immigration service was managing the investigation.
More top news
Baronness Altmann has urged for
Workers feel pessimistic about the future after the EU referendum, a new study shows.
The Prime Minister has created a taskforce and boosted the amount of money available to tackle 'barbaric' modern slavery.