A federal court may not weigh in on a case involving the controversial use of statistical sampling in Medicare false claims cases, according to recent legal arguments.

A panel of judges with the U.S. Court of Appeals for the Fourth Circuit heard oral arguments last week in the case of Agape Senior Community, which was accused by two former employees of submitting false Medicare claims for hospice services. A lower court previously denied the whistleblowers’ use of statistical sampling to back up their claims that the provider had defrauded the company.

Statistical sampling involves taking a small sample of claims potentially fraudulent claims, and comparing them to the total number of claims submitted by a provider during the period when violations were believed to occur.

During arguments on Wednesday, Judge Robert B. King repeatedly asked attorneys for the whistleblowers whether the lower court’s refusal to use statistical sampling evidence “wasn’t just a fact-driven ruling within the discretion of a district court judge,” instead of a statement against the method, Bloomberg BNA reported.

King also reportedly questioned whether the appeal was even valid, and noted that he believed the only issue in the case that should be ruled on by the court was whether the federal government can veto a settlement.

The panel’s apparent skepticism adds to a growing number of frustrating cases for both attorneys and providers debating whether statistical sampling can be used to prove False Claims Act allegations. Both federal and district courts of been split on the issue in recent years, according to Bloomberg.

Statistical sampling has drawn ire from long-term care provider advocates in recent months, with American Health Care Association President and CEO Mark Parkinson bashing it as a “giant sledgehammer” for the government to use to disregard actual proof in FCA cases. Statistical sampling was used recently in a case against Life Care Centers of America, which concluded last week with a landmark $145 million settlement.