BHP was so alarmed about the safety of chief executive Marius Kloppers – when he was insisting on much higher spot prices, as opposed to lower-priced long-term contracts for the sale of iron ore to China – that it sharply increased his personal security, according to former BHP chairman Don Argus.

“His safety was not as secure as it should have been at that time and we had to keep a very close eye on where he went and who he went with and what happened,” Mr Argus said. “This was worth megabucks.”