Eredivisie club FC Groningen say agents are being targeted by fraudsters setting up bogus transfers using real players to con them into paying fake fees.

Head coach Arno Jong said he had received dozens of calls from agents in recent weeks warning him about gangs using fake documents to set up deals in the name of his staff.

The club’s technical director Mo Allach said the criminals sent out contract offers, including salary details, to agents, asking them to sign and pay a fee for a medical exam and transport costs. Once the money is paid, the fraudsters vanish.

On one occasion an English player flew into Amsterdam expecting to be met by Groningen staff, only to discover that the deal was a scam.

“When nobody from our team turned up to collect him, he started to grow suspicious,” Allach told RTV Noord. “There is a big chance that his agent was taken in and paid money. The player had turned down other offers from clubs that were genuinely interested.”

The gangs also call agents posing as club officials. “I had a phone call recently from an agent who was enthusiastic about an offer that we’d supposedly sent to him,” De Jong said. “He wanted to make a follow-up appointment, but the offer turned out to have come from the fraudsters.”

Allach’s name was on the bottom of another fake contract sent to the Danish defender, Julius Madsen, offering him a four-year deal worth €12,000 a month plus a car.

Allach, who has filed an official police complaint of identity fraud, said the criminals’ methods were sophisticated, but they made mistakes that gave them away, such as quoting salaries including tax rather than pre-tax amounts.

Other Dutch clubs, including PEC Zwolle and Roda JC Kerkrade, have been targeted in the same way, Groningen’s managing director Frank van Mosselveld said.

He added it was easy for agents to fall for scams during the busy summer transfer period. “When an agency is dealing with 20 deals at the same time, things like this can slip through. They [the gangs] run a very slick operation.”