Sixteen Iraqi nationals were rescued from a lorry on the A22 in East Grinstead on Saturday.
The occupants of the vehicle waved to catch the attention of passing motorists who flagged down the driver. Emergency services assisted in the release of 13 men, two women and a child from the back of the vehicle. Two of the men were taken to hospital suffering from dehydration. The remaining people were provided with water and medical assistance. The nearby Trinity Methodist Church was used as a refuge centre, and immigration enforcement officers arrived to assist.
The A22 London Road was temporarily closed while the incident was ongoing.
The Crawley Neighbourhood Response Team said that the priority was the welfare of the people in the lorry.
The driver, a 63 year old man of no fixed address was arrested on suspicion of facilitating illegal immigration and was taken into police custody.