Finance Minister Mairtin O Muilleoir has been urged to temporarily stand down from his post as a scandal over the alleged coaching of a committee witness continues to grow.
In another dramatic day yesterday, the DUP made an official complaint to the Stormont Standards Commissioner and Sinn Fein suspended a party member after he allegedly made contact with a witness to an inquiry into Northern Ireland's largest ever property deal.
On Thursday, Sinn Fein MLA Daithi McKay apologised and resigned from the Assembly after admitting he had inappropriate contact with loyalist blogger Jamie Bryson before he gave evidence to the finance committee over the controversial sale of the Nama portfolio.
Last night, Ulster Unionist finance spokesman Philip Smith said Mr O Muilleoir, who was on the finance committee at the time of Bryson's appearance, should stand down until the matter has been investigated.
"Investigations should be carried out swiftly and transparently and, given the fact that he has been named, that can best be assisted by Mairtin O Muilleoir standing aside until an investigation is complete," he added.
DUP chairman Maurice Morrow also submitted a complaint about Mr McKay to the Assembly Standards Commissioner, founded on Stormont's code of conduct, which binds Assembly members to act with integrity and to avoid bringing the parliament into disrepute.
Sinn Fein chief whip Caral Ni Chuilin said: "Sinn Fein welcomes the involvement of the Assembly Standards Commissioner, and we will fully co-operate in any investigation. This investigation should be conducted swiftly and its conclusions expedited so that the facts are clearly established."
Sinn Fein will have to co-opt another party member to take over from former North Antrim Assembly member Mr McKay within the next seven days to avoid triggering a by-election.
Yesterday, the party suspended party worker Thomas O'Hara, who is accused of communicating with Mr Bryson before he gave explosive evidence to Stormont's finance committee about the efforts of Ireland's bank for bad loans to dispose of its Northern Ireland portfolio to American investors.
Mr Bryson was at the time preparing to name former DUP leader Peter Robinson in connection with the case.
The then first minister strongly denied seeking to benefit from the agreement involving US investors and the National Asset Management Agency (Nama).
The deal two years ago by Nama with US investment giant Cerberus, involving the £1.2bn sale of a Northern Ireland property loan portfolio, has been dogged by controversy after £7m linked to it was found in an Isle of Man bank account.
Critics have claimed the arrangement included multimillion-pound fixer fees.
None of the Twitter messages indicated that Nama-related information came to Mr Bryson from Sinn Fein.
Nama was established in Ireland at the height of the financial crisis to take property-linked loans off the books of bailed-out banks. It sold 800 property loans to Cerberus, a multibillion-pound fund.
The £7m was paid into an account controlled by a former managing partner of Belfast-based law firm Tughans, Ian Coulter, who resigned after it was unearthed.
Tughans, which was involved in the Nama transaction as subcontractor for Cerberus's US lawyers, Brown Rudnick, insisted it was not aware of the transfer.
All parties involved in the 2014 transaction deny wrongdoing.