Capricorn has since been successfully negotiating with Bernie Ecclestone about a new long-term race contract.
But Rhein Zeitung newspaper has now claimed that Capricorn has not paid the second due instalment to the Rhineland-Palatinate state.
Citing sources, the report said the amount of 5 million euros became due on July 31. To date, Capricorn has only paid one instalment in the same amount.
"It is assumed that Capricorn's financing from banks has come to a standstill because the European Commission has postponed several times the decision on the legality of the sale," Rhein Zeitung reported.
A spokesman for the financial recovery experts in charge of the Nurburgring insolvency said: "We have a timescale shift for the second purchase instalment.
"We still expect the sale to go ahead," he is quoted by Speed Week.
And Capricorn chief Robertino Wild told Auto Bild it is "untrue" the payment delay is in fact due to the company's own financial problems.
"This is a completely normal process. The operation of the business is going very well," he added.