McDonald’s has expanded its investigation of former CEO Steve Easterbrook to see if the company’s human resources department covered up his or any other worker’s misconduct. Mr. Easterbrook left McDonald’s after it was learned that he engaged in inappropriate sexual relationships with employees at the company. The fast-food giant later sued its former CEO, alleging that he lied about the extent of his inappropriate activity while he was employed. Mr. Easterbrook disputes the charges.