A special meeting will be held at Castlereagh Borough Council tonight to decide how to replace disgraced politician Iris Robinson.

It is understood councillors are expected to vote to hold a costly by-election after it emerged several elected members would block any attempts by the DUP to co-opt another party colleague into Mrs Robinson’s seat.

The meeting comes just two days after detectives with the PSNI’s Organised Crime Branch swooped on the council premises as part of a police probe into allegations made about the wife of First Minister Peter Robinson.

Mrs Robinson was forced to resign from her position at the local authority after details emerged about her financial dealings on behalf of her former young lover, Kirk McCambley.

It is alleged Mrs Robinson, who sensationally admitted to having an affair and trying to take her own life earlier this year, solicited £50,000 from two property developers in 2008 to bankroll Mr McCambley’s new business venture, The Lock Keeper’s Inn, then failed to disclose her interest when the lease was awarded by the council.

The revelations prompted Castlereagh to launch an independent inquiry to find out if any elected member or official committed any act of impropriety as a result.

This external investigation by Deloitte LLP has since been suspended after the PSNI announced it was conducting an investigation into the claims made in the BBC Spotlight programme.

The Assembly’s Standards and Privileges Committee has also said it had put its own probe on hold pending the outcome of the police inquiry.

On Saturday police officers with the specialised unit visited Castlereagh council buildings to examine records concerning the lease of the Lock Keeper’s Inn.

The team, who have already questioned Mr McCambley in relation to the allegations, spent around nine hours going through documents and computers as part of the probe.

The visit by police is sure to add further embarrassment to the council which has been put under the media spotlight since details emerged about Mrs Robinson’s business dealings.