Bradford City fans hit by an internet hacking fraud after buying tickets to the club’s League Two play-off final victory at Wembley are being asked to complete questionnaires to help police establish ‘patterns’ behind the scam.

Ticket Zone, the third-party agency used to sell tickets on behalf of the club, has written to Bantams’ supporters whose credit and debit accounts have been hacked by fraudsters, asking them to provide information to help with a criminal investigation.

The Telegraph & Argus last week reported how a stream of City fans complained of finding fraudulent payments from their accounts after booking tickets for the play-off final online, including the Reverend Dale Barton, of St Clement’s Church in Barkerend, Bradford, whose account was targeted for about £3,000.

It was also revealed fans of Brentford, who lost to Yeovil in the League One play-off final on Sunday, were affected after using the Ticket Zone site.

Last Thursday, the company said police had been called in to investigate what its inquiries had indicated was a “man in the middle” attack, where customers’ details were being intercepted and copied before their details reached a queuing site it uses, which is operated by a Danish company.

It added that checks on Ticket Zone’s website and protective infrastructure had shown all data was found to be clean and protected.

In an update this week, the company said it was asking for customers’ help to establish the ‘nature of the fraud’.

A spokesman said: “The nature of these exploits means that establishing patterns is of key importance in trying to determine the nature of the fraud, how it was applied and by whom. With this in mind Ticket Zone has invited a number of fans to complete a questionnaire which is aimed at gathering information which might help the investigating parties.

“Although the investigations are now likely to take some time, please rest assured that the club and Ticket Zone are doing everything they can to assist the inquiry.”

Anyone with any information for Ticketzone, which will be passed on to police or independent IT forensic specialists, should e-mail customerservices@ticketzone.co.uk.