Media playback is unsupported on your device Media caption Dr Andrew McCormick named Dr Andrew Crawford while giving evidence to Stormont's PAC

An adviser to former first minister Arlene Foster exerted influence over a flawed renewable energy scheme, a senior civil servant has said.

Dr Andrew McCormick said that, without direct evidence, he understood Dr Andrew Crawford influenced the decision to keep the Renewable Heat Initiative (RHI) running.

Mrs Foster set up the scheme in 2012 when enterprise minister and Dr Crawford was her then adviser.

Mr Crawford denies the allegation.

The RHI or "ash for cash" scandal, as it has become known, led Stormont's deputy first minister Martin McGuinness to resign from powersharing with the Democratic Unionist Party in protest and forced the collapse of the executive and a snap election.

Mrs Foster, from the Democratic Unionist Party, had refused to stand aside while an investigation into RHI was carried out.

The aim of RHI was to increase consumption of heat from renewable sources but businesses received more in subsidies than they paid for fuel, and the scheme became heavily oversubscribed.

It could lead to an overspend of £490m over the next 20 years.

Dr McCormick told Stormont's Public Accounts Committee (PAC) on Wednesday that initially no advice was given to Mrs Foster that she needed to get cost controls into the RHI as the uptake was low when she was minister.

The Economy Department senior official added that she followed her officials' advice on the scheme and that "ministers have the right to expect civil servants will get this kind of thing right".

Mrs Foster had moved on from the department by summer 2015.

In a statement Mr Crawford said in discussing RHI with the Department of Enterprise, Trade and Investment special adviser, he "would have been offering informal advice and assistance as a colleague to my successor in the department and not on behalf of the finance minister or the party".

"However, as I pointed out to the BBC in December I did not attempt to keep the RHI scheme open at the original tariff against the wishes of the minister. Indeed, I specifically stated on 31 July 2015 that the department, 'will need to make changes from 1st October'," he added.

Image caption Dr Andrew Crawford was an adviser to the then enterprise minister Arlene Foster when the RHI scheme was created

Who is Dr Andrew Crawford?

A son of a farmer from Beragh in County Tyrone, Dr Andrew Crawford is a former employee of the Ulster Farmers' Union.

He was an assistant to the former DUP MEP Jim Allister before the North Antrim politician quit to form the Traditional Unionist Voice (TUV).

Dr Crawford was an adviser to Arlene Foster when she was enterprise minister during the time the RHI scheme was created, and followed her to the Department of Finance and Personnel last year.

Jonathan Bell, who succeeded Arlene Foster as enterprise minister, accused him of preventing the closure of the scheme, but Dr Crawford has denied that claim.

These days, he advises another DUP minister, Michelle McIlveen, in the Department of Agriculture, Environment and Rural Affairs.

Dr Crawford's poultry-farmer brother is a claimant of the RHI scheme.

Civil servants wanted to cut the rate paid to businesses involved in the scheme in July 2015. It was eventually reduced that November but not before a massive surge in the number of applications.

Dr McCormick said insider information may have had a significant impact on the £490m overspend.

He said there was "an extra level of information" in the renewable heating industry in the summer of 2015 that the RHI tariff could be reduced, so people should "get in quick".

Image caption Former enterprise minister Jonathan Bell (top right) in attendance during Dr McCormick's evidence

Dr McCormick added that anonymous letters showed the information came from his department.

Among the other revelations made by Dr McCormick to the PAC were:

A meeting with former enterprise minister Jonathan Bell to review ministerial papers in December may have been recorded "without my knowledge or consent"

He is aware of at least one case in which energy consumer watchdog Ofgem has been talking to the PSNI over possible abuse of the RHI scheme

About 90% of 1,400 people had objected to a request by the Department of the Economy to be named as beneficiaries of the RHI scheme. He said the department is now going through the individuals on a case-by-case basis to see if they can be named in line with the Data Protection Act

The department did not know about flaws in the RHI scheme in the summer of 2015, so conversations over closing the scheme or introducing cost controls were "not seen as sinister".

Earlier, the Nolan Show revealed Dr McCormick believed a DUP special adviser had exerted influence to delay cost controls.

It said that Dr McCormick told the DUP of his concerns but had no evidence. The DUP confirmed to the programme that Dr McCormick told the party of his belief.

Jonathan Bell was in the public gallery while Dr McCormick gave evidence to the PAC.

He broke ranks from the DUP when he made serious allegations about how the scheme was run in a BBC interview in December. He was later suspended from the party..

Speaking under parliamentary privilege on Tuesday, Mr Bell also claimed he was told when he was minister that two DUP special advisers' "extensive interests in the poultry industry" would prevent scrutiny of the RHI scheme.

The advisers, Timothy Johnston and John Robinson, and the DUP denied the claims.