The startling spike in oil prices to their highest level this year on Tuesday was caused by a rogue broker who placed a massive bet in the Brent oil market, triggering almost $10m (€7m) of losses for his company.

PVM Oil Associates, the world’s largest over-the-counter oil brokerage, said on Thursday it had been the “victim of unauthorised trading”. The privately owned company said that as a result of the unauthorised trades it had been forced to close substantial volumes of futures contracts at a loss.