Motherwell have demanded immediate payment of a "substantial debt" owed by Cardiff City for the transfer of defender Paul Quinn. Quinn joined the Bluebirds last summer for a fee in the region of £300,000, reports BBC Sport.

Well say the money owed has been due since January, which would suggest payment of the fee was staggered.

"The board have been very patient with Cardiff given the financial pressures they have faced," said chief executive Leeann Dempster.

"However the interests of our shareholders, employees and fans are being jeopardised by the failure of Cardiff City to pay the debt that they have outstanding.

"We have made clear to the board of Cardiff that we are left with no option but to pursue every possible avenue of recourse to secure our own club's interests. We hope that this matter can be resolved in an orderly manner."

Cardiff City chief executive Gethin Jenkins said: "We are fully aware of the debt owed to Motherwell and we are working to resolve the issue as soon as possible."

It is the latest blow for the Bluebirds, who are under a transfer embargo imposed by the Football League because of continuing concerns over unpaid tax bills.

The club face a winding-up order at the High Court on 11 August over an unpaid PAYE tax bill owed to Her Majesty's Revenue and Customs which stands at £1.3m.