Developers Arrowcroft and Frogmore Real Estate Partners will face the costs of the failed Croydon Gateway project.
Plans to radically redesign the area were rejected by secretary of state Hazel Blears and the appeal period has now passed.
With no backing from Croydon Borough Council, developers could be facing write-off costs of £7 million, Property Week has reported.
The plans included a 12,500-seat arena and were devised to raise Croydon’s national profile and make the most of its transport links.
Arrowcroft had said it would build nearly 900 hundred new homes, a landmark 35-storey tower and more than 500,000 sq ft of office space.
Ms Blears recently refused the council’s compulsory purchase order raised on the site.
However, development could still go ahead at the site, albeit by a rival scheme from Foster & Partners.