Iris Robinson is still under suicide watch, says the DUP
Comments made about Iris Robinson in some Sunday newspapers are "ruthless lies", the DUP has said.
In a statement on Sunday night, the party said Mrs Robinson remained in hospital under 24-hour suicide watch.
The party condemned stories in some of that day's newspapers as "complete fabrication" and "pure fantasy".
Police searched Castlereagh Borough Council offices on Saturday as part of their inquiry into accusations made about Mrs Robinson's financial affairs.
A statement released by the council said the visit was arranged with them beforehand.
"All relevant personnel were aware of the visit and co-operated fully and transparently as has been the case from the start of the investigation," the statement said.
"Any records removed were computer records and this required IT personnel working in conjunction with the police IT personnel.
"There was absolutely nothing sinister in this visit whatsoever."
BBC Spotlight reported that Mrs Robinson - wife of Northern Ireland First Minister and DUP leader Peter Robinson - obtained £50,000 from two developers to help her teenage lover open a cafe business.
She then attended the council meeting during which the cafe lease was awarded to Kirk McCambley but allegedly broke the law by not declaring her financial interest.
The PSNI organised crime branch is carrying out an investigation.
In the statement released by the party, it claimed Mrs Robinson had been the target of "relentless smear and invention".
Official inquiries into Peter Robinson's conduct are still under way
The party said legal action would be taken.
It refuted the suggestion that Mrs Robinson was planning "a Tiger Woods-style public relations offensive as she gears up to a return to public life".
"The truth is that Iris remains in hospital under acute psychiatric care and under 24-hour suicide watch as a result of the unremitting and ruthless lies and attacks against her," the statement said.
It added that she had paid a "high price" for her "one indiscretion" and accused some of "a clear attempt to pursue her to the grave and destroy the lives of all her family".
Mrs Robinson resigned as an MP, assembly member and councillor following the Spotlight programme.
A special meeting of Castlereagh Council will take place later on Monday to discuss a replacement for her seat.