Soaring ticket prices and transport costs at this year's World Cup will expose fans to cyber fraud and scams as supporters are attracted by fakes in the mistaken belief they have bagged a bargain, an industry expert has warned.

Scam artists are active around every major global sporting event but there is an increased danger with World Cup tickets more expensive than at any previous edition, Nuno Sebastiao, the CEO and co-founder of Feedzai, told Reuters.

"Large gatherings like a World Cup are a scammer's dream," said Sebastiao, whose company works with banks around the world to detect and prevent fraud and other financial crime.

"The cost of these events is fairly high. And people are always trying to get a good deal somehow. And that's what these criminals prey on.

Tackling financial crime

"A football fan is not a high-income person like you'd see in other sports. So there's more propensity to be the victim of a scam because you really want to go, you really want to see the game, but you just don't have the money."

FIFA did not immediately respond when asked for comment about what advice it would give fans attending the tournament, and if any special measures had been put in place.

A report released earlier this month by The Knoble, a nonprofit network focused on tackling financial crime, forecast that the World Cup would fuel more than 28,500 suspicious financial transactions globally.

The main areas of fraud are expected to be around ticketing, travel and online scams, and Sebastiao warned much of it is run by large criminal networks and is sometimes state-sponsored.

Cyber fraud and scams around major sporting events also fuel human rights abuses, Sebastiao said.

"There's slave labour involved in these gigantic call centres," he added.

"They take their passports and force them to work slave hours to commit phishing and scamming attacks."

Illegal migration

Such exploitation by criminal networks is also seen on the ground around venues, including in the sex trade.

"When we see people being arrested, some of them are themselves victims," Sebastiao added.

"They're victims of human trafficking. They're forced to do that because they're illegal immigrants.

"Whenever there are these large gatherings, there are people who are trafficked for sexual exploitation."

Santa Clara County's Human Trafficking Task Force reported that when the Super Bowl was held in Northern California earlier this year, 29 traffickers were arrested and 73 sex trafficking victims were recovered, including 10 minors.

A similar operation will be put in place when the same San Francisco Bay Area Stadium hosts six games at this year's World Cup in June and July.