“Corey Lewandowski will be going on to other endeavors and we very much want to thank him for his service. He will no longer be associated with Trump World,” said Taylor Budowich, a spokesman for Mr. Trump. Mr. Budowich said that Pam Bondi, a former Florida attorney general and Trump adviser who had been working with Mr. Lewandowski at the super PAC, Make America Great Again Action, would now oversee the effort.

Whether Mr. Lewandowski remains permanently banished from Mr. Trump’s orbit remains to be seen. After serving as Mr. Trump’s original campaign manager, he was fired in June 2016 after conflicts with Mr. Trump’s children and a series of incidents that the Trump family worried had cast the candidate in a negative light. But a month later, Mr. Trump began reaching out to Mr. Lewandowski again, and he was soon back in the fold.

Aides to Mr. Trump insist this latest incident is different, particularly because it involves a donor to the former president. The donor, Trashelle Odom, made the allegations about Mr. Lewandowski in a statement that was first reported on Wednesday by Politico and that was later provided to The New York Times.