Mrs Robinson broke the law by not declaring her financial interest in a business deal
The wife of NI's first minister broke the law by not declaring her financial interest in a business deal.
BBC Northern Ireland's Spotlight programme said Iris Robinson, an MP, an MLA and a councillor, obtained £50,000 from two property developers.
The money was paid to her 19-year-old lover to help him launch a cafe. She later asked him for £5,000 for herself.
Mrs Robinson, who tried to kill herself after her affair, was said to be unable to comment for health reasons.
Spotlight also reported that her husband Peter Robinson became aware of the money she had obtained from the developers.
The programme said that while he pressed his wife to return the money, he failed to tell the proper authorities about the transaction, despite being obliged to act in the public interest by the
"While I have learned from Spotlight for the first time some alleged aspects of my wife's affair and her financial arrangements, I will be resolutely defending attacks on my character and contesting any allegations of wrongdoing," he said.
Much of the information in the programme came from Selwyn Black, a former RAF chaplain, who worked for Mrs Robinson for two years. He showed the programme makers over 150 text messages he received from Mrs Robinson.
Iris Robinson obtained £50,000 for Kirk McCambley with whom she was having a sexual relationship
Iris Robinson said in December that she was retiring from public life because of an ongoing battle with mental illness.
On Wednesday, she released
in which she admitted that she had tried to take her own life after what she described as a brief affair.
In an interview in response, Mr Robinson said that he was "devastated" and "deeply hurt" but that he had forgiven his wife and would not leave her.
Spotlight revealed that the man with whom Mrs Robinson had the affair was Kirk McCambley, now 21, and the joint owner of Lock Keeper's Inn off the Shaw's Road in south Belfast.
The programme reported that a sexual relationship between the two began in the summer of 2008. Mrs Robinson then revealed to Selwyn Black she intended to set up Mr McCambley in business.
At that time Castlereagh Borough Council, on which Mrs Robinson serves as a councillor, had advertised for a tenant to run a cafe at a new project on the banks of the River Lagan.
Mark Simpson, BBC Ireland Correspondent
At first it seemed that the family turmoil of Peter and Iris Robinson was simply a personal matter, but now it has become political. It has been a sudden change.
As the couple's marriage troubles were splattered over every media outlet in Belfast earlier this week, even their most bitter opponents held back.
There was no party-political gloating or opportunism. The public appeared to be overwhelmingly supportive too. The revelations were such a surprise that the reaction of most people was simply to gulp.
However, no sooner had the credits rolled on the BBC Spotlight programme at 11pm on Thursday than politicians started reacting by text, telephone and Twitter.
The most significant response came shortly after 1am, when Ulster Unionist Party leader Sir Reg Empey e-mailed a statement calling for an investigation into the conduct of Mr Robinson. The political ceasefire is over and Mr Robinson faces a bruising battle for survival.
The programme reported that Mrs Robinson then sought to provide Mr McCambley with capital to open the business.
She obtained a total of £50,000 from two developers, Fred Fraser, now deceased, and Ken Campbell to fund the project.
Spotlight reported that while Mrs Robinson was asking Mr Campbell for the money, she also lobbied on his behalf for one of his building projects in her parliamentary constituency.
Mr McCambley said he received two cheques, which he invested in kitchen equipment and furniture.
He also told the programme that after he received the money Mrs Robinson had then asked him to give her £5,000 in cash.
Spotlight reported that in July 2008, six weeks after Castlereagh Borough Council advertised for expressions of interest in the cafe project, only one applicant met the criteria - Mr McCambley.
The deal was sealed on 28 August and Iris Robinson was in attendance as the council authorised the signing of the lease.
The laws covering local government state that once Mrs Robinson had a financial interest in the business, she was obliged to declare it at any meeting she attended where it was being considered. She failed to do so.
Peter Robinson is under pressure over his wife's money affairs
As an MP, she was also legally obliged to declare the £50,000 she obtained from the developers in the register of members' interest at both
where she served as an MLA, and
She failed to do so.
Some time later, Mrs Robinson's relationship with Mr McCambley ended. At some point afterwards, she decided that he should pay back the money that had been given to him.
Mrs Robinson told Mr McCambley that half the money should be paid to her and the other half to a church in east Belfast where her husband's sister worked as a pastor.
Mrs Robinson told adviser Selwyn Black about wanting to help Mr McCambley
It is understood she later decided that the money should be returned to Ken Campbell.
When Peter Robinson found out about his wife's financial dealings, he insisted that the money should be returned.
However, he did not tell the proper authorities despite being obliged by the ministerial code to act in the public interest at all times.
On Thursday, Mr Robinson's solicitors said he was thoroughly satisfied that he has at all times acted properly and fulfilled all requirements, and would robustly challenge any allegation to the contrary.
They said that Iris Robinson was too unwell to respond.
The DUP released a brief statement after the programme which read: "Following allegations made about Peter Robinson in the BBC's Spotlight programme on Thursday 7th January 2010, Mr Robinson will be consulting his legal team on Friday."
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.