Stephen Nolan has vowed to continue to do his job after DUP MP Gregory Campbell repeated that he "would keep digging" into the broadcaster's affairs.

The East Londonderry MP said the Northern Ireland public wanted to know what political leaders were doing to stem the projected £490million loss to the public purse on Tuesday's Radio Ulster Nolan show when asked as to who was responsible for failing to implement tariff caps.

"In January 2017, the public want to know what we are doing now," said Mr Campbell.

"We need to resolve these issues. As a result of yesterday are we closer or further away?

BBC presenter Mr Nolan said he and his team would continue to ask who was responsible for the Renewable Heating Incentive scandal as well as what they were going to do about it.

"Yes," responded Mr Campbell, "and as you put it previously you are 'going to keep digging' and as I responded 'digging works both ways'."

Mr Nolan replied: "You dig away.

"I think the last time you said this people responded asking if you were threatening me?"

Mr Campbell came back: "Why would you ask that?

"Here is the point Stephen. You are very good at posing questions - as I have said on a number of occasions - and for which you are very highly and very secretively paid out of the public purse.

"The point is, you are not very good at answering them.

"That's the point, that's the digging that I am talking about."

Asked if the DUP had anything to tell the public about why cost controls were not put in place, if it would reveal to the public the reasons ahead of an election, Mr Campbell said an inquiry would have answered those questions.

"It could have been set up, I would have thought in a week or two, and could have been asking those types of questions and we would have been very, very content to abide by the outcome.

"That would have been an independent and judicial led outcome."

Asked again if the DUP had a response, Mr Campbell said he didn't know and he was not an Executive minister at the time the botched RHI scheme was establised.

"Sinn Fein have made a series of demands - it's our way or no way they have said.

"People have to make up their minds who they want to respond to this.

"How we fix the problem, not walk away from it but fix it, that is how we get it resolved.

"That's what people want to see."

Later in the programme a caller described Mr Campbell's "digging" remark as a "disgrace" and that the MP was effectively saying the broadcaster's card was being marked.

Stephen Nolan added: "You all pay me very, very well.

"My job is to ask questions and I will continue to do that.

"There was a similar approach taken by Mr Campbell before and I think we followed that up with the Jonathan Bell interview and the Arlene Foster interview.

"I'll continue to do my job and let's leave it at that."

Belfast Telegraph