Tony Blair told the BBC he would try to help the pupils affected

Prime Minister Tony Blair had told the BBC that getting the youngsters back out to Germany for another game was "something we need to work on".

But the Department for Culture, Media and Sport (DCMS) later warned it would be hard to source the required tickets.

Pupils from Worcs, Dorset, Hants, Lincs and Oxfordshire were hit by the fraud.

It will be very difficult to find 400 tickets DCMS spokeswoman

Portsmouth Football Club has also promised to try to find tickets for the children.

Manager Harry Redknapp and owner Alexandre Gaydamak visited pupils at Mayville High School in Southsea to tell them that the club would do everything it could to help.

The victims, aged between 11 and 16, were turned away from the matches on Saturday after their tickets failed to materialise.

They returned home on Monday, with many said to be devastated they had missed out on a once-in-a-lifetime opportunity.

Disappointed pupils returned to Mayville High School in Portsmouth

Shrewsbury-based travel operator Activ4 said it had been made aware of a scam involving its ticket supplier on Friday after its bank discovered fraudulent activity.

Police in the Thames Valley and Kent said they were investigating an account registered to a person in Slough, and a company in Swanley.

On Monday evening Mr Blair told a phone-in for football fans on Radio Five Live: "I think the Sports Minister Richard Caborn is trying to sort something out.

"I don't know what exactly can be done, but obviously for them it's terrible and it's something we need to work on to make sure they can get out there.

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"Usually there is a very strict boundary (between sport and Government) but on something like this we will try to do what we can to help."

But a DCMS spokeswoman said that while the department was keen to look at what could be done, it did not want to raise the youngsters' hopes.

She said: "It will be very difficult to find 400 tickets. We are going to try to do our best."

Linda Owens, headteacher at Mayville High School, from where 23 boys travelled to Cologne, said: "The whole point of the trip was to see a World Cup match, to get the flavour of what it would be like, the excitement of it.

"But the boys have been amazingly good, despite how devastated they obviously are."

Also affected were 30 boys from Portchester School, Bournemouth, Dorset; more than 40 pupils at North Bromsgrove High School, Worcestershire; 25 at Caistor Grammar School, Lincolnshire; and 11 from Drayton School in Banbury, Oxfordshire.