PARIS — A Human Rights Watch report this summer accused the French police of “gratuitously and systematically” using pepper spray on migrants, including children, in the northern French city of Calais and routinely confiscating their sleeping bags and other belongings.

Although the police disputed that account after it was released in July, a 70-page report by the Interior Ministry published earlier this week found “it plausible that there was a breach in security force doctrine and ethics.”

“Even though it doesn’t represent formal proof,” the ministry’s report said, testimony indicated that there had been “an abusive use of tear gas” by the police on at least one occasion and that the police had not shown their identification on other occasions, the report’s authors said.

The Interior Ministry report again raises questions about the French government’s treatment of the hundreds of migrants who gathered in Calais, hoping to cross the English Channel to Britain.