Take That fans have been left upset after tickets they bought for the band's Progress Tour failed to arrive.
The City of London Police's fraud unit has launched an investigation after an unconfirmed number of fans complained about tickets purchased on the website, ticketindex.net.
Emma Gittens, from Cheshire, paid £700 for ticket to see the band perform with Robbie Williams in Manchester on Sunday (June 5), but they still haven't arrived.
She told BBC News: "I got an e-mail through a couple of days ago saying their allocation of tickets hadn't been successful and they had tried everything they could to get these tickets.
"I was told I would receive a refund that day but it is still not in my account."
Fans have also complained that they have not been able to contact anybody at Ticket Index about the problem.
A message posted on the company's website on May 26 said: "We are currently experiencing technical difficulties with our phone lines. We are hoping for this to be fixed within the next 2-3 hours.”
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