An illegal immigrant was on the run in the UK today after smuggling himself into Britain underneath a coach full of Border Agency officials, the Home Office confirmed.
The immigration officers were not aware of the stowaway until they had completed their journey through the Channel Tunnel from France and had arrived at their depot in Folkestone.
It is understood the man, who hid in a small space between the fuel tank and the chassis of the coach, was seen disembarking, but was not caught by officials.
A Home Office spokeswoman said: "An illegal entrant entered Dover by hiding underneath a coach returning from France Coquelles. The coach was contracted by the UK Border Agency.
"A full investigation is being conducted.
"This is further evidence of the extreme and dangerous illegal measures that are being taken to enter the UK.
"We will continue to work closely with the French authorities, travel industry and port operators to protect the UK borders to combat illegal immigration."
Earlier this month, Britain promised £15 million to tighten border controls in French ports where hundreds of would-be migrants gather in the hope of smuggling themselves into the UK.
The cash will pay for new technology to search vehicles and goods heading for Britain.
A pilot of the hi-tech systems will be carried out at Calais before being extended to Boulogne, Dunkirk and the Channel Tunnel terminal at Coquelles.
In June, a study by The London School of Economics, commissioned by the Mayor of London Boris Johnson, estimated that there were 618,000 illegal immigrants in the UK.