FOUR-and-a-half year old Stormont investigation into the conduct of Peter and Iris Robinson has been completed but its publication has been further delayed by a legal challenge.
It took almost four-years to produce the report but a legal challenge from Mrs Robinson's solicitor at the end of last year has added further delays.
The investigation was ordered in January 2010 after revelations about Mrs Robinson's financial dealings and her affair with 19-year-old Kirk Mc-Cambley.
The inquiry was initially delayed for more than a year after the police launched their own investigation into the affair. However, after the Public Prosecution Service said no criminal charges would be brought, the assembly's investigation resumed.
The assembly's standards commissioner Douglas Bain said the report was completed in November 2013. However, he said it could not be passed to the relevant Stormont committee because of a legal challenge.
But members of the assembly's standards committee have criticised the length of time taken to complete the probe.
Alliance MLA Anna Lo said it was "extraordinary" that the assembly had to wait more than four years for the commissioner's report.
"I am puzzled and disappointed that this has taken so long," she said.
"There is a great deal about this investigation and report that is in the public interest and in such circumstances it's important that it is turned around promptly. I don't think four years is acceptable."
The South Belfast MLA said the legal challenge was unavoidable but that the investigation should have been completed sooner.
"It's obviously more complicated than the usual cases the commissioner investigates but in order to show the workings of the assembly are transparent and to ensure we maintain the public's confidence, it should have been finished much sooner," she said.
"When it takes so long you have ask what the point is? The political landscape has changed and one of the investigation's subjects left politics some time ago."
Fellow committee member and Green party MLA Steven Agnew said the time taken to complete the report was "unsatisfactory".
He said he believed the commissioner had been frustrated in his task.
"People are entitled to mount a legal challenge but my concern is that the commissioner is being deliberately frustrated in his efforts to get to the truth," he said.
The Irish News tabled a series of questions to the commissioner about the investigation and the report but he declined to comment.
The probe was launched in January 2010 after a BBC documentary revealed that then DUP MP and MLA Iris Robinson, had an affair and procured £50,000 in loans from two property developers for her teenage lover to finance a business.
She failed to declare any interest in the restaurant, despite serving on Castlereagh Council, which had given the business approval to open.
Mrs Robinson was subsequently expelled from the DUP and later retired from politics.
The BBC Spotlight programme claimed that when her husband found out about the financial aspects of his wife's relationship he insisted the money be returned.
However, he did not tell the assembly authorities about the deal despite being obliged by the Stormont executive's ministerial code of conduct to act in the public interest at all times.