Best Buy founder and chairman Richard Schulze is to step down after an internal investigation found he failed to alert the board that chief executive Brian Dunn was having an affair with a female employee. The probe found that Schulze “acted inappropriately” by not telling the retailer’s audit committee when he first heard allegations of Dunn’s infidelity.

Dunn resigned last month, and the electricals giant originally claimed it was for business reasons. However, it emerged Best Buy was investigating whether he misused company resources during the affair. The investigation, which ended yesterday, showed that Dunn did not misuse resources but he exercised “extremely poor judgement” in the relationship.