Spurs were contacted by a Croatian middle-man saying FC Twente had mandated him to sell Holland under-21 striker Luc Castaignos, and the club were presented with a document supposedly signed by Twente chairman Joop Munsterman.
After being contact by Tottenham, alarm bells rang at FC Twente with Munsterman having signed no such document. The club have reported the matter to the Dutch FA, the KNVB, asking them to pass it on to UEFA and FIFA.
An FC Twente statement read: "There has been an attempted fraud when a forged mandate, giving a person the authority to act of our behalf, surfaced. Unbeknown to FC Twente, a player has been offered with this forged document to an English club.
"The forgery has been made known to the KNVB, with the request to pass it on to UEFA and FIFA and take the appropriate measures."
Gert-Jan Nijweide, FC Twente's finance director, said: "We have recently been informed of this scam from England. We have sent a letter to the persons who have used the false document, ordering them to stop immediately."