Finance Minister Máirtín Ó Muilleoir has denied knowing about a back channel of communication between a Stormont committee's chairman and a witness.
He was responding to calls to step aside during an investigation into how Stormont's finance committee chairman handled its Nama inquiry.
Daithí McKay resigned as a Sinn Féin MLA last week amid claims he coached a loyalist blogger before his appearance.
Jamie Bryson implicated Peter Robinson as benefitting from the Nama deal.
The then first minister of Northern Ireland and former leader of the Democratic Unionist Party strongly denied he had sought to benefit in any way from the £1.2bn property deal.
A special meeting of the finance committee is to take place on Tuesday morning to discuss the ramifications of Mr McKay's resignation.
Leaked Twitter messages between Mr Bryson, Mr McKay and Sinn Féin member Thomas O'Hara were obtained last week by the BBC's Nolan Show and The Irish News.
Mr Ó Muilleoir, who was on the committee, was directly referenced in one direct message from Thomas O'Hara's Twitter account to Mr Bryson's which said: "I'm trying to establish what Máirtín or someone could jump on and say there's no way we can turn him (Jamie Bryson) away, this is credible, relevant and in the public interest."
Ulster Unionist Leader Mike Nesbitt and Alliance deputy leader Naomi Long have called for Mr Ó Muilleoir to step aside during an investigation, which Sinn Féin has said it would welcome.
But Mr Ó Muilleoir said attempts to link him to the scandal were "no more than petty party politicking".
"I had no part in or knowledge of these inappropriate communications," he said.
Analysis: Mark Devenport, BBC NI Political Editor
The finance minister insists he is going nowhere. Máirtín Ó Muilleoir says he was in the dark about the private messages exchanged with Mr Bryson and was astonished his name was mentioned in the conversations with the loyalist.
There is no clear timeline yet for the investigation into the matter by the Assembly Standards Commissioner.
But MLAs on the current finance committee are expected to reconvene as soon as Tuesday to discuss the ramifications of Daithí McKay's resignation.
The National Assets Management Agency (Nama) is the Republic of Ireland's "bad bank", set up to deal with toxic loans after the 2008 property crash.
It sold its Northern Ireland loans portfolio to a US investment firm for £1.2bn in 2014.
The Stormont inquiry was set up last year to investigate an allegation made in the Dáil (Irish parliament) that a politician or political party in Northern Ireland stood to profit from the loan sale.