SembCorp Marine's decision to appoint its own external auditors to investigate unauthorised currency bets made by its former group finance director is raising eyebrows. Some believe the move could potentially compromise the independence of the investigation; they say appointing a completely independent accounting firm is the preferred best practice. SembCorp Marine (SembMarine) had announced on Monday that its finance director, Wee Sing Guan, had entered into various unauthorised foreign exchange transactions - which have resulted in unprecedented losses of as much as US$248 million at SembMarine. If fully liable, the losses would far exceed the company's profits last year of S$238.4 million. The oil-rig builder also announced that same day that it had relieved Mr Wee of his duties and taken steps to prevent the entry of any further unauthorised transactions.