Sara Danius, the first woman to be chosen as the academy’s permanent secretary, essentially its chief administrator, quickly severed its ties with Mr. Arnault and his organization, known as Forum. She also commissioned an investigation by a law firm to look into the academy’s financial and other support for Forum.

Ms. Danius was not rewarded for her efforts. Several of her allies quit in frustration, and last month her adversaries forced her out of the top post, although she remains a member of the academy. On the same day, Mr. Arnault’s wife, the poet Katarina Frostenson, also stepped down.

Ms. Danius’s demotion prompted mass protests by critics who said that a woman had been scapegoated for the sexual misconduct of a man, and punished for trying to introduce openness and accountability to a group that preferred to close ranks.

With the academy depleted, and its secretive workings exposed to unflattering scrutiny, the Nobel Foundation, which manages the industrialist Alfred Nobel’s legacy and oversees all of the awards, stepped in to warn that the scandal risked tarnishing the prizes as a whole.

“The crisis in the Swedish Academy has adversely affected the Nobel Prize,” Carl-Henrik Heldin, chairman of the Nobel Foundation, said in a statement early Friday. He said that while the award was intended to be given yearly, it should be postponed when the group choosing winners had a problem “so serious that a prize decision will not be perceived as credible.”

Now humbled, the academy says it has a long way to go to rebuild trust.

“Confidence in the academy from the world around us has sunk drastically in the past half year,” the acting permanent secretary, the literary scholar Anders Olsson, told Swedish Radio on Friday, “and that is the decisive reason that we are postponing the prize.”

Another member, the historian Peter Englund, wrote in an email: “I think this was a wise decision, considering both the inner turmoil of the academy and the subsequent bloodletting of people and competence, and the general standing of the prize. Who would really care to accept this award under the current circumstances?”