Checks will be made in Brussels before travellers board the train

It will mean UK officials can stop travellers with false or inadequate papers before they board trains and are able to claim asylum in the UK.

Home Secretary David Blunkett met Belgian Interior Minister Patrick Dewael in London to complete the deal.

Similar measures operate at the three French Eurostar terminals and stopped 9,000 people reaching the UK last year.

The measures agreed with France in 2001 reduced asylum applications at London's Waterloo Station - where the Eurostar terminates - by more than 90%.

All of this adds up to a further reinforcement of the border controls, the restrictions, the ability to pick up people who shouldn't be coming across the border at all Home Secretary David Blunkett

The deal with Belgium will set up UK immigration controls at the Brussels-Midi Eurostar station, with UK officers posted there full-time from as soon as next year.

Mr Blunkett said: "All of this adds up to a further reinforcement of the border controls, the restrictions, the ability to pick up people who shouldn't be coming across the border at all."

He said similar measures could be extended to the Netherlands soon.

"There is still a lot to do," said Mr Blunkett.

"This is another announcement of working with the French, the Belgians and in future the Dutch so that we can move our border controls on to the European continent and stop people claiming asylum."

Q & A: New immigration controls

A deal with Holland could mean immigration officers are posted at ports such as Rotterdam, as well as Vlissingen, where UK officials already operate a heartbeat detection sensor.

The Immigration Service's director of border control David Roberts said: "For a little while we have been exporting our frontier controls to where they are most needed.

"In 2001 there were many hundreds of people getting on the Eurostar without proper documents, and when they were dealt with by immigration officials on the train or at Waterloo they claimed asylum.

"We have reduced that by about 95%. It's a real success story and we want to extend that to Eurostar coming from Brussels."

Mr Roberts said that during one month in 2001, up to 700 people claimed asylum at Waterloo.

There is no evidence at all that what we've done at Calais has displaced hundreds and hundreds of people to other ports in the UK but we've got to be alert for that and we've got to watch the risks carefully David Roberts, Immigration Service

"Last month I think there was one, and normally there is none," he said.

He conceded that would-be immigrants could simply find another port of entry, and said that would be monitored.

"There is no evidence at all that what we've done at Calais has displaced hundreds and hundreds of people to other ports in the UK but we've got to be alert for that and we've got to watch the risks carefully," he said.

UK immigration officers have been working at Brussels-Midi station since April 2003 but only in an advisory capacity with their Belgian counterparts.

The deal will grant them full powers to interview would-be travellers and deny them entry.

The Home Office has also funded �9m of detection equipment in France and Belgium.

On Wednesday they showed off hi-tech equipment already operating at the Belgian ports of Ostend and Zeebrugge to detect stowaways and contraband in freight lorries.