USA regulators have fined a former hedge fund trader $30m for manipulating the natural gas market.

The Federal Energy Regulatory Commission (Ferc) levied the fine on Brian Hunter, Amaranth’s lead energy trader, for violating the Commission’s anti-manipulation rules.

The fine comes as President Barack Obama said a team was being assembled to look for fraud in the oil market.

Natural gas and oil are heavily traded commodities on which huge bets ride.

Mr Obama said the attorney general was assembling a team that would look for any evidence of market manipulation in the oil market, which is closely linked to – and trades in a similar way to – the gas market.

He pointed the finger at “speculators,” saying a new justice department task force would “root out any cases of fraud or manipulation” that may have caused higher prices.