In his most recent challenge to the results of the 2020 U.S. election, President Donald Trump this week cited a report claiming to show that thousands of noncitizens voted, a practice studies have found to be extremely rare.

Trump’s Truth Social post on Tuesday referenced a report published by the U.S. Census Bureau that he said checked “Voter Records from 2020 against their Citizenship Records,” finding 24,000 noncitizens voted illegally in just its initial search. The report is described as a “beginning analysis.”