Biarritz have appealed their relegation into the French third division.
The national rugby league (LNR), the body that oversees professional rugby in France, relegated Biarritz, Bourgoin and Narbonne into Federale 1 after enquiries by a financial watchdog co-run by the LNR and the French rugby federation.
"Proof has been delivered that the adjusted net position will be positive on June 30 2016 and the reserve fund sufficient to meet all obligations," the Basque club said in a statement.
Biarritz, the club of former France full-back and now federation vice-president Serge Blanco, were relegated into the Pro D2 in 2014 and have since struggled financially. They finished eighth in Pro D2 last season.
But it is only six years since they played in the second of their two losing European Cup finals and 10 years since the last of their five French titles.
In the first part of the 21st century, Biarritz were one of France's dominant sides, winning the French title three times in the five years from 2002-2006, playing in the 2006 and 2010 European Cup finals and winning the secondary European Challenge Cup just four years ago.
But two years after that they were relegated to the Pro D2 in a remarkable collapse of fortunes.
Talks of a merger with fellow Basques Bayonne - who have just been promoted back up to the Top 14 after one season in the second division - fell through as Biarritz continue to struggle financially.