Democratic Unionist leader Arlene Foster has sought legal advice following the publication of a highly-acclaimed new book on the Renewable Heat Incentive scandal, its author has claimed.

News Letter Journalist Sam McBride’s book Burned which was released on Wednesday has attracted unprecedented trade interest and is heading for a second print run.

It lifts the lid on the cash-for-ash allegations on how the Northern Ireland government paid £1.60 for every £1 of fuel the public burned in their wood-pellet boilers, leading to widespread abuse and the collapse of the power-sharing administration at Stormont.

It examines Mrs. Foster’s role in the scheme as enterprise, trade and investment minister with Mr. McBride writing that the Fermanagh-south Tyrone MLA’s “image of competence, likeability and attention to detail” was blown away after RHI exposed “how the woman who rose to become Northern Ireland’s first female First Minister had managed to do so because of a lack of scrutiny of her record”.

It also looks at Andrew Crawford, Mrs. Foster’s Fermanagh born private secretary who resigned in January 2017 after he was named in Stormont's Public Accounts Committee as attempting to delay the introduction of cost controls, he has repeatedly denied.

Mrs. Foster and other figures declined to be interviewed for the book.

Mr. McBride, whose book includes a chapter on Mrs. Foster entitled ‘Minister for Photo Opportunities’, says he has received legal correspondence sent on their behalf.

Commenting he said: "This book was never intended as any sort of hatchet job on the DUP, Arlene Foster, the Civil Service or anyone else who features in the story and I have sought to speak to all sides to understand what really happened," he said.

"I made that clear to Mrs. Foster and her colleagues when I asked them questions about what they had done. And so I am therefore disappointed that rather than answer what I believe were reasonable questions in the public interest, they responded with what I believe to be a spurious legal threat."

In the book, Mr. McBride writes how Mrs. Foster had long been lampooned by opponents as the ‘minister for photo opportunities’, such was the volume of PR photos of her which her department sent to newsdesks.

Mr. McBride has stressed that his book is a non-partisan investigation.

"Multiple DUP figures have publicly or privately acknowledged that I have done my best to honestly report this scandal and tried to do justice to the complexity of a story which is far more nuanced that the simple 'Foster is to blame' narrative pushed by some of the DUP's opponents.”

The book also reveals that Mrs. Foster and another former minister Jonathan Bell received large and extra-large turkeys from a poultry company that benefited from her government’s RHI scheme.

Mr. McBride explained that one question he posed to Mrs. Foster was on how many occasions did she "accept a free Christmas turkey, or other gifts, from Moy Park".

He writes in the book that at the heart of Mrs. Foster’s “disastrous response to the RHI scandal when it erupted was her failure to accept personal responsibility”.

‘Burned’ by Sam McBride is available in shops now.