An Afghan stowaway was discovered in Britain's elite Sandhurst army training college after hiding on an army coach that arrived from the European continent, the Ministry of Defence admitted Thursday.

The man hid on a bus travelling from a British army base in Germany, and ended up at Sandhurst -- where Princes William and Harry trained to become army officers.

A military source said the man was from Afghanistan.

The Sun newspaper said he was discovered by officers as they got off the bus. He had hidden in a stairwell by the toilet, the tabloid reported.

"We can confirm that an individual was discovered onboard a coach within the Royal Military Academy Sandhurst having stowed onboard during the coach's transit from Germany," a Ministry of Defence (MoD) spokeswoman said.

"He was detained before he left the vehicle and handed over to Thames Valley Police. The coach was provided and driven by a civilian contractor who has responsibility for the security of their vehicle.

And he added: "Security officers in all army establishments have been informed and reminded of security procedures to reduce the risk of a further incident of this nature."

The man is in the custody of Britain's Border Agency.

"As soon as this individual was discovered he was taken into custody, detained and finger-printed so he could be checked against a range of criminal and immigration watch-lists," a spokesman said.

"People with no right to be in the UK will be removed at the earliest opportunity."

Sandhurst, southwest of London, is Britain's top training academy for army officers. Several royals and heads of state and government are among its former cadets.

They include King Abdullah II of Jordan, Sultan Hassanal Bolkiah of Brunei, Crown Prince Sultan bin Abdul Aziz of Saudi Arabia, Tonga's King George Tupou V and Henri, Grand Duke of Luxembourg.

Damian Green, immigration spokesman for the main opposition Conservatives, said: "Even after all the security disasters of recent years, it still beggars belief to find that an illegal immigrant can not only smuggle himself into this country, but into Sandhurst on an army bus."

Earlier this week, the MoD confirmed that a member of staff at Sandhurst had been diagnosed with swine flu.

Truck drivers who fail to check their vehicles for stowaways can face fines of up to 2,000 pounds (3,240 dollars, 2,330 euros).