US regulators on Wednesday levelled fraud charges against three former executives of Computer Associates, including Sanjay Kumar, the US software company's former head.

The company is also to widen its own investigation into past accounting malpractice in an effort to reclaim some of the $1bn (?560m) in bonuses that were paid in the late 1990s to Mr Kumar and two other men who built the US software company, according to a person close to the group.