The Police Ombudsman for Northern Ireland has written to the Stephen Nolan programme to clarify remarks she made on air after unionist politicians questioned whether her office would treat complaints impartially.

Jacqui Durkin appeared on the programme on Thursday 13 August and discussed how her office handles allegations of sexual misconduct made against police officers. She said complainants should be treated with dignity and respect and should be believed in the first instance. Her comments led to calls for clarification from Ulster Unionist Party leader Jon Burrows and TUV leader Jim Allister.

In an open letter, Durkin said her words had been misinterpreted as suggesting she would decide the outcome of complaints before any investigation. She said no complaint alleging sexual impropriety by a police officer is predetermined, and that investigations must be thorough, evidence-led and impartial.

Durkin explained that there is a difference between treating a vulnerable complainant in a way that makes them feel believed and that their complaint will be investigated, and telling police officers to assume an allegation is true from the outset. She said her office investigates valid complaints fairly and independently.

Burrows, a former senior police officer, wrote to the ombudsman seeking assurances on impartiality. He said anyone who comes forward with an allegation of sexual abuse by an officer must receive compassion, support and empathy, but investigators must keep an open mind. He said failing to test all available evidence would harm both genuine victims and those wrongly accused.

Allister said a blanket policy of believing any complaint on sexual matters would effectively create a presumption of guilt. He said this contradicts the presumption of innocence and that the ombudsman's office has powers of arrest. Such a policy would make it difficult to establish reasonable suspicion, he said.

Durkin has said that alleged sexual impropriety accounts for 36 per cent of her office's most serious cases. One of those investigations involves a former officer who was arrested last year on suspicion of rape and dozens of other offences. Sinn Féin MLA Linda Dillon said the figure was damning and that such behaviour must be challenged and rooted out.

Durkin was appointed to the ombudsman role in June. Burrows also asked for a meeting to discuss the speed of investigations and delays in the ombudsman's office.