LONDON — The BBC struggled on Monday to contain a spreading crisis over its reporting of a decades-old sexual abuse scandal as two senior executives withdrew temporarily from their jobs in the wake of the resignation of the corporation’s director general, a move that encapsulated the worst setback to the public broadcaster’s status, prestige and self-confidence for years.

The BBC’s Web site said its director of news, Helen Boaden, and her deputy, Stephen Mitchell, had “stepped aside,” the latest moves since a flagship current affairs program, “Newsnight,” wrongly implicated a former Conservative Party politician in accusations of sexual abuse at a children’s home in North Wales in the 1970s and 1980s.

The BBC management said that while neither Ms. Boaden nor Mr. Mitchell “had anything at all to do with the failed ‘Newsnight’ investigation” of the politician, Alistair McAlpine, it “believes there is a lack of clarity in the lines of command and control in BBC News” because of an inquiry into a separate “Newsnight” debacle — the cancellation of a program a year ago into allegations of sexual abuse by Jimmy Savile, a longtime BBC television host who died last year at age 84. The BBC said the two executives would step aside until the end of that investigation, which is being conducted by Nick Pollard, a former head of the rival Sky News.

The BBC said its head of news gathering, Fran Unsworth, and Ceri Thomas, the editor of the current affairs radio program “Today,” would fill in for the executives who stepped aside.