A month after President Trump’s executive order barring people from seven majority-Muslim nations from entering the United States caused tumult around the country, the government’s accounting of how many travelers the ban affected remains unclear.

A total of 746 people were detained and processed in a 26-hour period immediately after a federal judge in Brooklyn blocked part of Mr. Trump’s Jan. 27 order, according to a list released by the government on Thursday.

The figure was nearly seven times greater than the 109 people that Mr. Trump said in a Jan. 30 message on Twitter had been “held for questioning” and Sean M. Spicer, the White House press secretary, said had been “inconvenienced.”

But, according to lawyers for some of those who were detained, 746 may be an incomplete figure.

At a hearing before Judge Carol B. Amon of Federal District Court in Brooklyn on Friday, those lawyers challenged the veracity of the government’s list, saying they knew of at least 10 people who had been detained who were not included in the tally.