The District may have to pay as much as $1 million to an outside laboratory to test DNA evidence after two audits found that the city’s own testing procedures were inadequate, two city officials said Tuesday.

District officials are scrambling to identify a DNA forensic lab that can review older cases as well as handle new cases.

Last week, the ANSI-ASQ National Accreditation Board, one of the national organizations that govern DNA labs, ordered the District’s Department of Forensic Sciences crime lab to immediately suspend all DNA case­work. The board concluded that the lab’s procedures were “insufficient and inadequate.”

The audit, which was published Friday, criticized the lab’s practices and said it was not in compliance with FBI standards. It ordered “at a minimum” the revalidation of test procedures, new interpretation guidelines for DNA mixture cases, additional training and competency testing of staff. Authors of the audit gave the D.C. lab authorities 30 days to address their concerns.

District officials, who spoke on the condition of anonymity because they were finalizing negotiations with alternative labs, said the city could expect to pay between $800,000 and $1 million for using the new lab. The officials said the costs would include handling new cases, reviewing past cases and using the alternative lab to revamp and revise existing practices. It is unclear how long city officials would use the new lab.

The expense comes just three years after the lab opened in a $220 million facility in Southwest Washington.

In March, The Washington Post reported about alleged problems that prosecutors said they found in some of the lab’s DNA analyses. The lab’s director, Max Houck, has repeatedly defended the lab, even after prosecutors said they found flaws with the analyses. Houck argued that his lab technicians followed the same protocols that many city and state labs across the country used in interpreting evidence.

But because of concerns among prosecutors, District officials ordered its own investigation of the lab’s practices. The city-ordered audit was delivered the same week as the separate audit ordered by the U.S. attorney’s office. Forensic experts, commissioned by the U.S. attorney’s office, found similar problems.

District officials said another part of the expense for using an alternative lab will include defraying the costs the U.S. attorney’s office assumed in using another lab to review past cases. A spokesman for the U.S. attorney’s office said the office has ordered outside reviews of 182 cases, which cost “hundreds of thousands of dollars.”

It remains unclear how many cases have been affected by the alleged errors performed by the District’s lab, but prosecutors have said the errors have not resulted in the dismissal of any cases or exonerations.