Sinn Féin MLA Daithí McKay has stood down as an Assembly member and been suspended from the party following allegation he coached a loyalist blogger to make allegations of financial impropriety against Peter Robinson.

And against allegations that Sinn Féin was party to a conspiracy against the former DUP leader and First Minister, the Deputy First Minister Martin McGuinness has insisted his party had no knowledge of the alleged contact between Mr McKay and blogger and flags protester Jamie Bryson.

The DUP also called for the police to investigate the matter.

It was claimed on Thursday that Mr Bryson was coached with the assistance of Mr McKay and another Sinn Féin member on how to make public allegations under the protection of Stormont privilege that Mr Robinson financially gained from the sale of the Nama properties in the £1.2 billion deal known as Project Eagle.

Mr McKay was then chairman of the Stormont finance committee which was hearing evidence relating to Nama and allegations that a “kickback” payout of £7 million was to be shared with some business and legal people and politicians.

At the time Mr Robinson said Mr Bryson’s claims were “scurrilous and unfounded” and that the loyalist blogger Mr Bryson delivered a “scripted performance that was little short of pantomime”.

In the wake of the claims, Mr McKay was interviewed on Thursday by senior Sinn Féin members, according to the party.

On Thursday afternoon, Sinn Fein chief whip Carál Ní Chuilín issed a statement, saying: “Daithí McKay has resigned as MLA for North Antrim with immediate effect and has been suspended from Sinn Féin. His letter of resignation has been submitted to the Speaker’s office.”

Sinn Féin sources said that Mr McKay had engaged in a “solo run” in allegedly “coaching” Mr Bryson. Several politicians such as the DUP’s Sammy Wilson and former Alliance Minister Dr Stephen Farry discounted such comments, stating that such was the internal discipline in Sinn Féin that no MLA would dare engage in such unilateral action.

‘Disturbing’

Mr McGuinness, however, insisted the party leadership had no knowledge of the contact with Mr Bryson.

“The allegations surrounding North Antrim MLA Daithí McKay are profoundly disturbing. If the allegations of inappropriate contact prove to be true, then Daithí McKay needs to seriously consider his position as an MLA,” he said shortly before Mr McKay’s resignation was announced.

“I want to state categorically that I had absolutely no knowledge of this exchange or contact. And having spoken to all relevant personnel in the Assembly I am now entirely satisfied that Sinn Féin had no knowledge of any such contact,” added Mr McGuinness.

The Irish News reported on Thursday that Mr McKay exchanged direct personal messages on Twitter in the period before Mr Bryson gave evidence to the Stormont finance committee in September last year about the Nama issue.

It reported that the MLA advised Mr Bryson to follow a separate Twitter account of a Sinn Fein member and adviser. It was that account holder which allegedly advised Mr Bryson how to draft and present his evidence to the finance committee which was then chaired by Mr McKay.

This Twitter account holder, who appeared to be well briefed on the workings of the Nama finance committee, advised Mr Bryson on how to make the allegations against Mr Robinson, it is alleged.

Mr Bryson in his evidence referred to a “Person A” as benefiting from the Nama sale and it was only at the end of his evidence that he said “Person A” was Mr Robinson.

The account holder advised Mr Bryson to use the tactic of referring to “Person A” and to only name Mr Robinson at the end of his evidence.

In a tweet to Mr Bryson he wrote, “Means that the committee cannot interrupt you and means that you do not have to say Robbo’s (Mr Robinson’s) name until the very end last second. So then it’s job done.”

After this allegation was made last September Mr Robinson described the claim as scurrilous and said, “I repeat, I neither received, expected to receive, sought, nor was I offered a single penny as a result of the Nama sale.”

Untenable

The Irish News and the BBC’s Nolan programme said they had transcripts of the tweets involving Mr McKay, the Sinn Fein adviser and Mr Bryson.

Ahead of the Mr McKay’s resignation the DUP Minister for Education Peter Weir said Mr McKay’s position as an Assembly member could be untenable. “If the allegations which are carried today are shown to be correct and accurate, I think it’s the most scandalous breach of the position of a committee chair that I’ve seen,” he said.

“The actions have been highly inappropriate and indeed, run a coach and horses through the processes of the assembly,” added Mr Weir.

In a tweet Mr Bryson wrote: “Absurd to suggest I was ‘coached’ by Sinn Féin. If, as is alleged, Sinn Féin were manipulated into assisting my passage to Department of Finance and Personnel; that’s a matter for them.”

Sinn Féin said it was only made aware of the allegations on Thursday. “Sinn Féin’s position has always been about getting to the truth about the sale of the Nama portfolio,” said a spokesman.

“Sinn Féin have only been made aware of these allegations today and if they are true, then this contact would be wholly inappropriate. If such contact did occur it was without the knowledge, involvement or sanction of Sinn Fein,” he added.

“Sinn Féin will pursue this serious matter urgently and robustly,” said the spokesman.