Top Spad privately asked for Foster's RHI files before scheme was exposed

The then Spad also used private DUP email addresses, rather than departmental accounts, meaning that the communication would not have been discoverable under the Freedom of Information Act.

Evidence published last night by the RHI Inquiry ahead of Mr Johnston’s appearance before it today suggests private DUP concern at the time.

Communications obtained by the inquiry show that around July 4, 2016, the day before the Audit Office report which first exposed the scale of the RHI overspend, Mr Johnston urgently sought from the then-minister responsible for the scheme, Simon Hamilton, and his Spad, John Robinson, “all submissions that were put to Arlene on the RHI scheme by DETI [her old department]”.

He went on to say that “we need this material discreetly today and when asking for it do so by phone call and not email”.

The inquiry asked Mr Johnston in writing why he had done so.

He said: “I wanted all relevant documents to try to establish what material had been submitted to the First Minister (FM) to provide an accurate record so that any comments and statements that were publicly issued in the aftermath of the NI Audit Office Report were in fact accurate. I recall this being part of a fact checking exercise of which the FM would have been aware.”

The inquiry asked Mr Johnston why he wanted the matter dealt with in a way that would not leave a trail.

He said: “I wanted the matter treated ‘discreetly’ because at that point I did not want it to become clear that we really were not aware of what were the facts during the period in question. I did not want it becoming clear that we had commenced a process of fact checking.”

When asked why he used party email accounts – rather than official government email addresses – for the communication, Mr Johnston said: “This was my practice for all of my period as a special advisor as I did not have access to official documents outside of office hours and I never adopted the procedure of using two phones. My department and ministers all knew that had always been the case.”

Pressed by the inquiry on why Spads and ministers “engaged in behaviour that was designed to avoid the creation of written records of their actions and what the reasons for such behaviour were”, Mr Johnston denied that there was “a general practice of behaving in a way of avoiding written records”.

However, he accepted that there were “many occasions when discussions between minister and advisors would not have been recorded”, adding that “the vast bulk of meetings between the First Minister and Deputy First Minister on how to resolve difficult political issues within government were rarely documented”.

He said that “Sinn Fein in particular were keen to exclude officials from meetings. Sometimes that was appropriate but on many other occasions it was not”.

There is also evidence which backs up allegations that Mr Johnston had a senior role among Spads and acted as an ‘enforcer’.

A message released by the inquiry shows that the Executive’s top spin doctor, David Gordon, sent an email in which he advised that a query from the BBC about the RHI scheme should be responded to with “a shorter statement, plus a scary TJ [Timothy Johnston] call to Nolan might be in order”. When asked what precisely was meant by “a scary TJ call to Nolan”, Mr Johnston simply said: “A call that would set out the FM and DUP version of events up to that point.”

Mr Johnston said it was “not unusual” for the DUP and Sinn Fein to deliberately keep issues from being discussed at the Executive to keep them away from the smaller parties.