Seven people, including four children, are facing deportation from the UK after they were arrested near Spalding.
The group, originally from Albania, were held by police on suspicion of entering the UK unlawfully after they were seen getting out a lorry in Low Fulney on Friday.
A 33-year-old woman, treated by paramedics after vomiting, four boys aged between 10 and 18 and two men, aged 21 and 37, were in the group.
They were kept in police custody and then handed over to UK Border Agency (UKBA) officials.
Robin Humphris of Lincolnshire Home Office Immigration Enforcement said: “When suspected illegal immigrants are found on lorries and arrested by police, we respond quickly.
“We work closely with the police to tackle illegal immigration and where someone is found to have no legal right to remain in the UK, we will take action to remove them.”
A Lincolnshire Police spokesman said: “Our job was just to hold the group until UKBA take over, ensuring that their welfare needs were met in the meantime.”