A family of four and a 17-year-old boy have been detained after being discovered in the back of a lorry at Cobham services on the M25.
Surrey Police officers were called at 11pm last night to reports of five people hiding in the HGV.
A Home Office spokeswoman said a 29-year-old woman, a 28-year-old man and two minors said they had travelled from Iraq and were released into temporary accomodation.
A minor who is said to be from Iran has been passed into the care of social services to be age assessed.
The spokeswoman said: "The Home Office will progress the cases of all five people in accordance with immigration rules.
"Where someone has no right to remain in the UK, we will take action to remove them."