The top strategist for the embattled super PAC backing Governor DeSantis’s campaign for the White House resigned on Saturday night in the latest sign of trouble for the Republican hopeful less than one month before voting begins with Iowa’s kickoff caucuses.

The top adviser, Jeff Roe, to that super PAC, Never Back Down, is the latest senior staffer to exit. Never Back Down has been the largest outside group supporting Mr. DeSantis’ candidacy.

Mr. Roe announced his departure on X, the site formerly known as Twitter, hours after the Washington Post published a story focused on internal disputes and suspicions between Never Back Down, the campaign, and other allies of Mr. DeSantis. The Post reported accusations of “mismanagement and conduct issues, including numerous unauthorized leaks containing false information.”

“I can’t believe it ended this way,” Mr. Roe wrote on X, sharing a statement in which he said he “cannot in good conscience stay affiliated with Never Back Down given the statements” in the story, which he said were false.

Numerous senior members of Never Back Down have been fired or resigned in recent weeks, including two chief executives, the group’s chairman, and its communications director. At the same time, Mr. DeSantis’s Florida allies have created a new super PAC, Fight Right, which had earned the public blessing of the DeSantis campaign.

The Associated Press reported earlier this week on growing concern among some within Mr.DeSantis’s operation that interactions between his campaign and his network of outside groups were blurring the lines of the legally permissible.

Super PACs are legally barred from directly coordinating with campaigns. But multiple people familiar with Mr. DeSantis’s political network say that he and his wife had expressed concerns about Never Back Down’s messaging as his Iowa poll numbers stagnated — concerns the campaign then shared with members of Never Back Down’s board, according to multiple people briefed on the discussions who spoke on the condition of anonymity in order to share internal discussions.

Some of the board members then relayed the Mr. DeSantis’s team’s wishes to super PAC staff, which was responsible for executing strategy, the people said. Mr. DeSantis’s campaign has denied any wrongdoing.

Never Back Down had taken an unprecedented role in the election, overseeing functions normally handled by campaigns. The group was charged with organizing voters through a massive door-knocking and get-out-the-vote operation. It has spent tens of millions of dollars on commercials this year.

Mr. Roe, one of the Republican Party’s most prominent strategists, ran Senator Cruz’s 2016 presidential campaign, which beat  President Trump in that year’s Iowa caucuses, and also worked as an adviser on Governor Youngkin’s victorious campaign. But he had little preexisting relationship before this year with Mr. DeSantis, who has long struggled to maintain close relationships with political consultants.

Weighing in on Truth Social from Las Vegas, where he was watching a UFC fight, Mr. Trump late Saturday cheered the news, writing “Jeff Roe is out—GAME OVER for DeSanctimonious!” he wrote. Mr. DeSantis has staked his campaign on Iowa, where Trump is leading by wide margins in recent polls.

The super PAC was seeded with more than $80 million from DeSantis’ political accounts this spring.