Hundreds of pupils have returned home from Germany after falling foul of a World Cup fake ticket scam.
The children thought they had tickets to watch World Cup games
Nearly 400 schoolchildren from across the UK became caught up in the "fraud" after arriving in Germany on Saturday.
Parents in Oxfordshire, Hampshire, Dorset, Worcestershire and Lincolnshire were told they had match tickets as part of a £410-a-head tour.
The travel company, Activ4, said it had been made aware of a scam involving its ticket supplier on Friday afternoon.
It confirmed that its tickets were supposed to have been supplied by an agency based in Kent.
James Collins said it was hard to break the news to the boys
In a statement Kent Police said: "We can confirm that we are investigating an allegation of this nature and that it is against a company in Swanley.
"This is in the early stages of investigation and at this stage we are not working with police in Germany."
Thames Valley Police also confirmed they were carrying out an investigation.
A spokesman said: "Police in Slough are conducting an investigation into an allegation of fraud involving payments for a number of World Cup tickets for school children from the UK.
"Officers are investigating an account registered to a person in Slough in connection with the inquiry.
"At this time no arrests have been made. However, officers continue to pursue several lines of inquiry."
More than 40 pupils at North Bromsgrove High School in Worcestershire, 25 pupils from Caistor Grammar School in Lincolnshire and 11 children from Drayton School in Banbury, Oxfordshire, also missed out on the games after their tickets failed to materialise.
In a statement Activ4 said "the issue was made apparent when our bank discovered fraudulent activity" and police in both the UK and Germany had been notified and were investigating.
"Activ4 is outraged by this callous act of fraud and will continue to offer the police our full co-operation," the company said.
Thirty boys from Portchester School, Bournemouth, Dorset, and a party of 23 from Mayville High School in Portsmouth returned home on Monday.
James Collins, PE teacher at Mayville High School, said: "We booked this tour in September 2005. They [the pupils] have been saving their pocket money for the last year.
"We got to Germany and on the day of the match our tour operator said that unfortunately there were no tickets. There had been a problem with our agent."
He said his group of boys were "absolutely devastated" when he told them.
Mr Collins said: "We got promised a trip of a lifetime, a once in a lifetime opportunity, and it was taken away at the last minute so we are so angry."
Chris Bradey, head teacher of Portchester School, a specialist sports college, said: "The tickets had been sourced for them [the children] by the tour operator - and the tour operator has done nothing wrong - but let's just say the sourcing of the tickets proved to be of doubtful provenance."
Andrea Gritt, whose 11-year-old son Jazz was one of the 30 returning pupils, said she was shocked by what had happened.
She said: "Although the staff made it really good and they've had a good time, the point was to go to a World Cup match."
Andreas Herren, spokesman for Fifa, said: "This is absolutely regrettable for the young kids, because they have been deprived of a great opportunity to watch World Cup action.
"But unfortunately the incident confirms what Fifa and the local organising committee have been warning against from the start, that only tickets from official sources should be acquired and not other sources of a dubious nature."