LONDON — The BBC struggled 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 following the resignation of the corporation’s director-general in the worst setback to the public broadcaster’s status, prestige, and self-confidence in years.

The BBC’s website said its director of news, Helen Boaden, and her deputy, Stephen Mitchell, had ‘‘stepped aside,’’ the latest moves since 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.