First Minister Peter Robinson has urged a Stormont watchdog to "closely investigate" reports of political parties abusing expenses.
The DUP leader said it was "absolutely essential" that a robust system to ensure that public money was spent how it should be and he would be urging the Assembly Commission to investigate. Amid calls for an independent inquiry and new system of allowances, the Assembly was asked to debate next week how some MLAs used their office cost allowances.
A number of MLAs have already tabled urgent questions following a BBC NI Spotlight probe which again raised concerns over how Sinn Fein and DUP figures in particular get an allowance of up to £70,000 a year.
Deputy First Minister Martin McGuinness, Mid Ulster MP Francie Molloy and other Sinn Fein representatives were accused of paying thousands of pounds in rent to cultural and historical societies which could not be shown to exist.
Mr McGuinness insisted his party had always been "above board" on expenses and had nothing to fear from a new audit.
The DUP MP Ian Paisley and Executive Minister Arlene Foster were also called into question over their constituency offices in Ballymena and Enniskillen.
In the programme - the first of a two-part investigation - the former chairman of a Westminster standards watchdog, Sir Alistair Graham, said there should be a detailed investigation into the allegations.
Justice Minister David Ford added his weight to demands for a full and independent probe "carried out in a way that prevents any political party from interfering or preventing the facts from coming out".
TUV leader Jim Allister, who requested the allegations are raised as a 'matter of the day' in the Assembly next Monday, argued: "Public confidence in Stormont was already very low. (Now) it is at rock bottom. At a time when the public sector is under such pressure it is particularly galling to witness such abuse of the system."
He has asked the Assembly Commission, responsible for running Parliament Buildings, what action it proposes to take and whether any of the societies received funding from culture or rural development funds.
Spotlight accused Sinn Fein figures of funneling tens of thousands of pounds into basically "bogus" cultural and historical societies. MLA Daithi McKay had until recently been paying £12,000 in rent for two adjacent offices in Dunloy. It also said three DUP representatives, MP Ian Paisley and MLAs David McIlveen and Paul Frew, all have allowances for the same office in Church Street, Ballymena. Mr Paisley said, however: "There is no secret in all of this. I am a tenant in the building and I pay rent." DUP Enterprise and Industry Minister Arlene Foster was said in the programme to have used an office provided by a businessman rent-free.