Gas consumers in Northern Ireland could have been affected by the alleged manipulation of wholesale prices in other parts of the UK, the utility regulator said on 15 November 2012.
The Financial Services Authority (FSA) and Ofgem are looking into the claims, which were made by a whistle-blower who was active in the market.
All of the UK's big six energy suppliers have denied any involvement.
Speaking to Stormont's Enterprise Committee, Shane Lynch said that the gas market-fixing could have had a "knock-on effect" if it was found to be true.
He explained this was because there was no wholesale market for gas in Northern Ireland.
"We simply import all our gas into the market and those gas prices are set in a different UK market," he said.
"If anybody was buying gas on that day that was being sold to consumers in Northern Ireland, in theory, yes, they could have paid too much for it."
However, Mr Lynch explained that the allegations centred around some traders in wholesale gas who were said to be deliberately selling it for less than they could have asked for so they could profit from it in the long-term.
"If that is the case, that there was some form of manipulation to reduce the price, then consumers would have, in theory, benefited," he added.
The regulator also said that electricity and gas tariffs in Northern Ireland were currently cheaper than the rest of the UK, although for electricity, this was unusual.
"On average, over the last number of years, we (NI) have been about 10% more expensive than the Great Britain average price."
Mr Lynch also added that tariffs in Northern Ireland were "typically cheaper" than the Irish Republic.
"We are in a pretty good place at the moment, but it is difficult to see how sustainable this will be."
Department of Enterprise, Trade and Investment (DETI) officials also gave a briefing on the Energy Bill.
The Executive has previously said it wants to create a more sustainable energy system.
DETI is seeking to bring in a new law which would create greater powers for sustainable energy and additional regulatory measures relating to natural gas and electricity.