A Maryland official acknowledged publicly Wednesday, for the first time, that none of the 500,000 coronavirus tests the state purchased from South Korea in April were used to diagnose whether people had the virus.

More than 496,000 of the tests were handed back to the manufacturer as part of a deal for replacement tests, acting health secretary Dennis Schrader told the Board of Public Works. About 3,500 were used as lab workers tried to validate them.

His statement contradicted assertions by Gov. Larry Hogan (R) last month after The Washington Post reported that none of the original tests had been used. Asked by MSNBC’s Chuck Todd about that specific Post finding, Hogan said: “They worked great. They were using them all over the country. We were using them.”

The Post reported Nov. 20 that Hogan, after widely touting the $9.46 million test purchase, withheld the tests’ problems from the legislature, state spending authorities and the public.

According to interviews and documents reviewed by The Post, the tests could not easily be used because the instructions and materials they came with did not match those given emergency authorization by the Food and Drug Administration.

After one private lab declined to use the tests, the state told another private lab not to use them and quietly ordered replacement tests from South Korea for an additional $2.5 million.

Schrader gave information about the tests in response to questions from Comptroller Peter Franchot (D), who sits on the Board of Public Works along with Hogan and Treasurer Nancy K. Kopp (D).

Lt. Gov. Boyd K. Rutherford (R) attended the board meeting in Hogan’s place Wednesday.

Schrader told the board that health officials have gotten similar questions from the Department of Legislative Services (DLS), which is reviewing emergency purchases related to the pandemic.

“We’ve answered a lot of these questions in detail,” Schrader said. “We’ve given them all our records.”

On Tuesday, however, DLS’s legislative auditor, Gregory Hook, told lawmakers in a letter that his office had “experienced some difficulty” obtaining information about the tests from state agencies.

Hook said he and his staff “were somewhat taken aback” by The Post’s report, “which contained certain information that OLA [Office of Legislative Audits] auditors had requested a number of weeks ago from the Maryland Department of Health, but had not yet received.”

Hook told lawmakers who’d requested the review this summer that he didn’t expect it to be completed by the end of the coming legislative session, which runs from mid-January to mid-April.

Among other things, Franchot wanted to know why the state paid for replacement tests after finding problems with the originals.

“We were under pressure, and we were negotiating with the manufacturer, and the manufacturer was not willing to just replace the tests,” Schrader said. “They felt they were entitled to some remuneration.”

Schrader said laboratories that initially tried to use the tests discovered “they were slow, and for lack of a better, nontechnical term, they were clunky.”

When the state public health lab looked at the tests, called polymerase chain reaction (PCR) tests, “they realized that the formula that we had gotten was an early formula and was not consistent with what the FDA had on its website,” Schrader said.

The manufacturer, LabGenomics, applied for emergency authorization from the FDA in late March, according to records obtained by The Post. By April 18, when Maryland received the first shipment of tests, the FDA had cleared the import to proceed. But the FDA did not issue emergency authorization for their use until late April.

Once labs in Maryland examined the tests, they realized the kits didn’t match what the FDA had authorized, according to interviews and records. One key difference was the lack of a “control” to ensure the efficacy of a step in the test analysis process called “extraction.”

The FDA recommends that PCR tests include such controls to receive authorization. A spokesman for the FDA declined to say whether the agency asked LabGenomics to make that change. LabGenomics also declined to comment.

Schrader said Maryland officials discussed the problems with LabGenomics in mid-May.

“They talked to the folks in Korea and said, ‘Hey, this test has this difficulty, and it’s not exactly the formula,’ ” Schrader said. “They said, ‘You’re right, we’ve got the formula updated. We can get you the new tests.’ ”

The first shipment of replacement tests arrived on May 21, records show. As of Wednesday, more than 435,000 had been used, health department spokesman Charles Gischlar said.

In June, the original tests were shipped from a Maryland State Police Forensic Sciences Division location in Pikesville to an office warehouse building in Ridgefield, N.J. It’s not clear what happened to them after that.

“They were picked up by the manufacturer,” Schrader said. “They took control of them. Where they actually sent them, we don’t know.”

Min Joo Kim in Seoul and Joyce Lee in Washington contributed to this report.