A Nebraska state lawmaker apologized on Monday after he publicly cited a persistent but debunked rumor alleging that schools are placing litter boxes in school bathrooms to accommodate children who self-identify as cats.

State senator Bruce Bostelman, a conservative Republican, repeated the false claim during a public, televised debate on a bill intended to help school children who have behavioral problems. His comments quickly went viral, with one Twitter video garnering more than 300,000 views as of Monday afternoon, and drew an onslaught of online criticism and ridicule.

Bostelman initially said he was “shocked” when he heard stories that children were dressing as cats and dogs while at school, with claims that schools were accommodating them with litter boxes.

“They meow and they bark and they interact with their teachers in this fashion,” Bostelman said during legislative debate. “And now schools are wanting to put litter boxes in the schools for these children to use. How is this sanitary?”

The rumor has persisted in a private Facebook group, “Protect Nebraska Children,” and also surfaced last month in an Iowa school district, forcing the superintendent to write to parents that it was “simply and emphatically not true”.

Bostelman had said that he planned to discuss the issue with the CEO of the Nebraska department of health and human services. He also alleged that schools were not allowing kids to wear flags, but didn’t give specific examples. In 2016, Lincoln’s public school district briefly asked students not to fly American flags from their vehicles after one flag was pulled from its holder, but school officials later apologized.

The false claim that children who identify as cats are using litter boxes in school bathrooms has spread across the internet since at least December, when a member of the public brought it up at a school board meeting for Midland public schools north-west of Detroit.

The claim was debunked by the district’s superintendent, who issued a statement that said there had “never been litter boxes within MPS schools”.

Still, the baseless rumor has spread across the country, and become fuel for political candidates, amid the culture wars and legislative action involving gender identification in schools.

Hours after his remarks, Bostelman backtracked and acknowledged that the story wasn’t true. He said he checked into the claims with state senator Lynne Walz, a Democrat who leads the legislature’s education committee, and confirmed there were no such incidents.

“It was just something I felt that if this really was happening, we needed to address it and address it quickly,” Bostelman said.

The furor over public school restrooms comes as a growing number of conservative states seek laws to ban transgender students from using bathrooms that match their gender identity.