People smugglers are moving migrants from France to the UK by hiding them inside cars on ferries - before the stowaways jump into lorries on the vehicle deck mid-way through the voyage.
A former Border Force chief informed about the newly revealed smuggling method - illustrated today in a MailOnline graphic - described it as 'really useful intelligence' and said it may require improvements to security on ferries and at Dover.
Lorries were the most common route used by stowaways before tighter security around ports and the Channel Tunnel prompted smugglers to change their tactics to favour small boat crossings.
These have hit record levels this year, with 1,200 arriving by boat on Saturday alone.
Migrants stowing away in lorries typically board them in northern France before remaining hidden until the vehicle has entered Britain.
