The so-called independent regulator of the Green Deal programme is actually controlled and owned by the 'Big 6' energy companies, ClickGreen can reveal.
Gemserv is being paid £5.8 million of taxpayers' money to administer the registration scheme, which will help households increase energy efficiency and cut down on their utility bills.
But a clear conflict of interest has become apparent after it was found the largest shareholders in Gemserv are actually the energy companies themselves - British Gas, Scottish & Southern, ScottishPower, nPower, E.ON and EDF.
They are known to be against the detail of the Green Deal programme and ClickGreen revealed earlier this year that Energy Minister Greg Barker had blocked the publication of correspondence between his department and the energy giants discussing worries about the payment structure.
The Green Deal is the Government's flagship programme to help businesses and households access energy efficiency measures, such as loft or wall cavity insulation, and cut down on energy use.
The scheme was supposed to be independent and impartial, and allow the cost of the improvement measure to be spread as repayments are collected from the property utility bills until the debt is completely repaid.
But tonight some operators in the scheme are questioning how the Green Deal could possibly claim to be impartial if the scheme's regulators are answerable to the Big 6.
And others in industry are asking if Gemserv should be allowed to continue to decide which of the smaller companies can or cannot now be registered to operate under the Green Deal scheme.
The 'Big 6' firms and their subsidiaries own more than 75% of Gemserv and even receive dividend payouts from their shareholdings.
British Gas is the biggest stakeholder in Gemserv, controlling 16.72% of the company and is this year understood to have made more than £27,500 from its dividend pay-out alone.
Gemserv's latest Annual Report revealed that “some large shareholders are represented at Board level as Non-Executive Directors” but their identities were not published.
After landing the £5.8 million contract to become the Oversight and Registration Body (ORB) in June, Gemserv, with partner REAL, now has the power to screen companies who wish to receive accreditation and operate under the programme.
At the time of the announcement, Climate Change Minister Greg Barker said: “We need to make sure all the Green Deal assessors, installers and providers get our stamp of approval to ensure the highest level of consumer protection for householders and businesses under this scheme.
“I am delighted that Gemserv has risen to the challenge and is going to take on this very important role."
Tonight, a DECC spokesman said the decision to award Gemserv the ORB contract was made following a competitive tendering process under EU procurement rules.
He added: “This is one of a number of Green Deal related contracts. Others include the national energy saving advice service, the Green Deal Ombudsman, administration of the incentives scheme and the EPC Register.
“The ORB is the only contract that Gemserv has been awarded."
John Oddi, managing director of South East-based Crystal Windows and Doors, said no mention of Gemserv's control and ownership by the Big 6 is made apparent on its corporate website or brochures.
He added: “We are genuinely concerned. Sales firms like Crystal provide genuine competition for the energy companies both in terms of pricing but also quality and customer service. It's frightening to think that our competitors could have any influence as to who trades in this market and who doesn't.
"This body appears to receive public money and should be wholly independent.
“We have previously sent various emails to the CEO of Gemserv expressing our concerns about that organisation. He has simply ignored all emails.”
A spokesman for Gemserv, which also helps operate the Microgeneration Certification Scheme, was unavailable for comment tonight.