Energy supplier RWE npower said Ofgem's report into its profits was "already out of date".
The energy supplier said in a statement: "RWE’s power stations in the UK made a loss of £51 million, a far cry from a 20% profit margin.
"For supplying Britain’s homes and businesses with electricity and gas, npower made a profit margin of just 3p in the pound”.
More top news
A huge wildfire has prompted the evacuation of an entire Canadian city.
The garden of paedophile friends of serial killers Fred and Rosemary West is being dug up by police after a tip-off.
A man has been arrested on suspicion of murder after a woman's body was found in south Wales.