During the Obama era up to 200,000 deportation cases were "administratively closed" without action, a move that left tens of thousands of illegal immigrants free to roam America, sometimes indefinitely, according to a new report.

When added to those cases still pending court action, it brings the backlog of cases to about 800,000, far more than previously known.

In the report for the Center for Immigration Studies, former immigration judge Andrew R. Arthur said that there are some 100,000 cases that were closed, but told Secrets that it could be as high as 200,000.

"My back-of-the-envelope calculations suggest at least 100,000 more are possible, for 200,000 on top of the 600,000 we currently have," said Arthur.

In his report, he said the exact number isn't known. "I believe that the Obama administration's use of the practice may have ‘cooked the books' as it relates to the true number of cases that are pending adjudication before the immigration courts."

The Trump administration has taken action to reverse the practice of letting authorities close the cases and is working to reschedule them, he added.

That's likely to create an even bigger immigration court backlog of about 2,400 cases per judge.

"The good news is that the Trump administration has reversed the practice of administrative closure of cases that are not a priority, and has effectively eliminated prioritization as well, returning ‘prosecutorial discretion' to its proper role as a law-enforcement tool to be used on a case-by-case basis, not a blanket abdication of authority," he wrote in the report titled, "The Immigration Court Backlog Is Larger than We Know."

While administratively closing some cases was a practice that increased under Obama, Arthur added that there is no legal authority for it. He wrote: "Don't go looking for this authority in the regulations, because it does not exist there." Quoting Justice, he said, "It is merely an administrative convenience which allows the removal of cases from the calendar in appropriate situations. Put another way, administrative closure allows the immigration courts to shelve cases that it does not want to, or cannot, deal with, at least at the time of closure."

He was part of a Center for Immigration Studies panel last week that reviewed the issue as well and the appeals process for those ordered deported.

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com