The Washington Post fact-checker on Tuesday gave Democratic Sen. Claire McCaskill (Mo.) four Pinocchios for claiming she was not in the Senate last year when Congress passed a bill that weakened the ability of the Drug Enforcement Administration to go after drug distributors as opioid-related deaths in the country continued to rise.

The Ensuring Patient Access and Effective Drug Enforcement Act has come under fire after a Washington Post/"60 Minutes" investigation found that the law "stripped the [DEA] of its most potent weapon against large drug companies suspected of spilling prescription narcotics onto the nation's streets." Following the report, President Donald Trump announced that his drug czar nominee, Rep. Tom Marino (R.. Pa.), one of the bill's main backers, had withdrawn his name from consideration for the position.

Lawmakers have been pressed about the legislation since the bombshell report was published, including McCaskill.

The Post rated McCaskill's claim that she was away from Congress because of breast cancer treatment as patently false. In reality, the Missouri Democrat held a 30-minute call with reporters telling them she was back at work on March 14, 2016, three days before the Senate approved the DEA bill by unanimous consent on March 17, 2016, at 6:25 p.m.

On March 16 of last year, McCaskill also cast a vote to oppose efforts to defund Planned Parenthood.

McCaskill had told CNN's Jake Tapper on Monday that she "did not go along with" the bill, adding that she was not even in the Senate at the time but would "like to believe" she would have opposed the measure.

"Now, I did not go along with this. I wasn't here at the time. I was actually out getting breast cancer treatment," McCaskill said. "I don't know that I would have objected. I like to believe I would have, but the bottom line is, once the DEA kind of, the upper levels at the DEA obviously said it was okay, that's what gave it the green light."

Contrary to her statement on CNN, records show that McCaskill had a full day of work on the day the DEA bill passed. She spoke on the Senate floor, cast a vote, and participated in a Senate hearing.

"[McCaskill] told CNN she'd ‘like to believe' she would have opposed the bill and stopped it. But the reality is that she was there—and she missed the opportunity that she seeks now. She earns four Pinocchios," the Post reported.

A spokesman for McCaskill acknowledged the senator's error, telling the Post, "It was sloppy on our part, and we take responsibility."

McCaskill was given an opportunity to correct the record Tuesday during an interview with NPR's David Greene, who told the senator, "I know you were dealing with some health issues and did not take a vote on this."

McCaskill did not correct Greene, instead staying silent and leaving the impression that she was away from the Senate at the time.

The Post has previously called out McCaskill for making false claims. Earlier this year, the paper gave the senator three Pinocchios for claiming she never met with the Russian ambassador to the U.S., when though she had tweeted about meeting with him.