The 50-year-old man was arrested on suspicion of immigration offences and was taken to custody in Parkside Police Station, Cambridge.
The vehicle was stopped at Cambridge Services near Swavesey shortly after 4.20pm yesterday (Thursday, February 24).
Police searched the lorry and found nine men and four women were inside.
The vehicle is thought to have begun its journey in the UK at Dover, Kent.
Cambridgeshire Constabulary was called to the scene by officers from another force, and East of England Ambulance Service sent multiple teams to the incident.
“They have since been handed to immigration.”
An East of England Ambulance Service spokesperson said: “We were called to Cambridge services on the A14 just before 5.30pm yesterday following reports a number of people had been found in the back of a lorry.
“Two rapid response vehicles, three ambulances, two vehicles from the Hazardous Area Response Team and an operations manager attended the scene.
“Thirteen patients – nine men and four women – were assessed at the scene and did not require transportation to hospital.”
An Essex Police team tweeted about the incident at around 6.25pm yesterday.
They said that roads policing vehicles from Chigwell, near London, traced the lorry to Cambridge Services where they were joined by other crews.
