A DUP special adviser has resigned following claims he exerted influence over the botched Renewable Heat Incentive (RHI) scheme.
Andrew Crawford, a former adviser to Arlene Foster, had been working at Stormont as special adviser to agriculture minister Michelle McIlveen.
His decision came after a Stormont committee heard claims that he influenced a decision to keep the flawed RHI scheme running when officials wanted to close it.
Mr Crawford denies the allegation and any wrongdoing.
The senior party adviser, from Beragh in Co Tyrone, is a former employee of the Ulster Farmers' Union and adviser to former DUP MEP Jim Allister.
He has a brother who is a poultry farmer and recipient of payments under the RHI scheme.
At a hearing of the assembly's Public Accounts Committee on Wednesday, senior civil servant Andrew McCormick said he understood that influence was being exerted by Mr Crawford to keep the scheme running at a high tariff level.
In a statement yesterday, Mr Crawford said: "In light of the allegations made at the Public Accounts Committee yesterday, I believe it is appropriate that I step back from my position in government and resign as a special adviser.
"I am conscious I have become the focus of the story.
"I want to see a full and independent inquiry set up immediately so that it will become clear that at all times I acted with complete integrity in all that I did.
"I will be happy to give a full account of all of my actions during this period to the inquiry and for due process to take its course.
"However, at this crucial time for Northern Ireland it is vital that I do not become a distraction from the real choice which faces the people of Northern Ireland."
Mr Crawford said he intends to support the DUP during the election campaign.
"At stake is the future direction of Northern Ireland and whether people want a future in which the DUP continues to hold a strong position or one where republicans dictate the political debate with insatiable demands," he said.
Mr Crawford was Mrs Foster's special adviser at the enterprise department when the RHI scheme was introduced.
The DUP leader said she accepted his resignation with regret, describing him as a "faithful servant" to the party and people of Northern Ireland.
"Anyone who knows Andrew Crawford knows he's a very private person and he didn't want to become the story," the former first minister said.
Mr Crawford's resignation came after another DUP special adviser stood aside from any future involvement in RHI after failing to declare a family link.
John Robinson's father-in-law receives payment from the energy scheme for two boilers.
The adviser to economy minister Simon Hamilton said he had no role in or benefit from his father-in-law's business, but was partially stepping aside to avoid the "accusation or perception of a conflict of interest".
RHI has been engulfed in claims of abuse including a farmer allegedly set to pocket around £1m over the next 20 years for heating an empty shed.
The state-funded scheme was supposed to offer a proportion of the cost businesses had to pay to run more environmentally-friendly boilers.
But the subsidy tariffs were set too high and without a cap, meaning it ended up paying out significantly more than the price of fuel – allowing claimants to get free heat and make a profit while doing so.
