IOWA CITY, Iowa -- More than 2,300 VA patients in Iowa and South Dakota were assigned to primary care "ghost panels," or doctors who no longer worked at their hospitals, a federal audit found.

Critics say the practice is a way that some VA hospitals have made their doctors' caseloads appear artificially small and within federal guidelines. It can also be disruptive for patients, who have to see different doctors if they need care and may face longer wait times.

The report issued Thursday by the Department of Veterans Affairs Office of Inspector General found the practice was limited to two health care systems — in Iowa City, Iowa and Black Hills, South Dakota — out of eight that serve 300,000 veterans in the upper Midwest. The report did not say whether those two systems benefited from using ghost panels.

It recommended the hospitals discontinue the practice, which violates a department policy that requires patients to be reassigned to new doctors when their primary care physicians leave. The practice also results in the publication of inaccurate data on doctor-to-patient ratios. But auditors found no evidence that patients were negatively affected because hospitals used other strategies to provide them needed care.

Nonetheless, Rep. Dave Loebsack, an Iowa Democrat, said in a statement Friday that anyone involved with creating ghost panels should be punished.

"The use of ghost panels at any Veterans Administration facility to misrepresent the true panel size is disconcerting," he said. "The fact that the VA has created an environment where the use of ghost panels appears to be in use across the nation is unacceptable."

The investigation came in response to a request by U.S. Rep. Timothy Walz of Minnesota after a whistleblower claimed the VA in St. Cloud, Minnesota, inaccurately reported the size of its primary care caseloads.

The investigation found no evidence that the St. Cloud VA used ghost panels but confirmed that hospital officials had under-represented its workload and staffing availability in flawed data provided to Walz and the general public.

In a joint statement, Walz and Rep. Tom Emmer, R-Minnesota, said the report "validates our most serious concerns."

"Misrepresenting panel sizes is completely unacceptable and a serious breach of the public trust. We call on the Secretary of the VA to hold anyone who intentionally misled veterans, members of Congress and the public accountable," they said.

Auditors in January found two ghost panels at the VA in Iowa City, Iowa, where 1,245 patients were assigned to doctors who had left for jobs at other VA facilities in November and August. They found two other such panels in Black Hills, where 1,056 patients were assigned to doctors who had left employment in September and October.

Hospital administrators in both states said they did not reassign those patients because they expected to hire replacement doctors who would then take over the workloads within months.

In Iowa, acutely ill patients were assigned to other physicians who had the capacity to treat them in the meantime and a pool of providers was used to help others, the report said. In South Dakota, the hospital used existing providers to manage those patients.

Both hospitals said they hired replacement doctors earlier this year, and the VA promised additional oversight to prevent the use of ghost panels in the future.