King & Wood Mallesons, the top end of town law firm, is reported to be under investigation by WorkSafe for overworking staff to meet deadlines during the financial services royal commission. A report in the Australian Financial Review says the investigation was triggered by a complaint about employee fatigue at the firm’s Melbourne office. Mallesons’ clients at the royal commission include AMP, Suncorp, Youi and IOOF during the commission hearings. “A source said KWM graduates were subjected to gruelling conditions, with some employees choosing to sleep at the firm’s Melbourne office rather than return home,” says the AFR. “Day and night shifts were allocated, so work could continue around the clock.” The royal commission has been a fee windfall for both the legal industry and for professional services firms, with the banks and others spending hundreds of millions on preparing for hearings. The ANZ Bank earlier this week booked legal fee expenses of $55 million related to the financial services royal commission. Comment is being sought from WorkSafe and from Mallesons. NOW WATCH: Money & Markets videos Business Insider Emails & Alerts Site highlights each day to your inbox. Follow Business Insider Australia on Facebook, Twitter, LinkedIn, and Instagram.