SHE'S a most unlikely revolutionary. A conservatively dressed middle-aged woman with a strict, no-nonsense air, Nuala O'Loan wouldn't look out of place at a gathering of DUP matrons. The British government obviously thought her a safe pair of hands when she was appointed police ombudsman. How wrong they were.

O'Loan's report into the murder of Raymond McCord jnr has shown collusion far worse than even some republicans thought possible. ExSpecial Branch bosses, accustomed to no one ever questioning their decisions, let alone integrity, are on the warpath. Ronnie Flanagan, O'Loan's old adversary, is under pressure to resign from his job inspecting British police forces. Not bad for a shy mother-of-five whom they predicted would never be a match for the wily Branch boys.

O'Loan's report was delivered in her customary restrained tones. But let nobody doubt her passion for the cases she investigates or those who have brought them.

"Nuala's been very worried about Raymond McCord snr, " says somebody who knows her well.

"She knew he was already exhausted and, now the report has been released, she's concerned he'll be deflated. She's constantly on the phone to him, checking he's okay."

The personal, female touch is her trademark.

On hearing the stories of those who have lost loved ones through collusion, she confesses to breaking down in her office. "But I put away my tears to do the job properly - I'm no use to anybody if my emotions take over."

She's one of the most non-egotistical people in public life. Her desire that her work alone is the focus can lead to extreme measures.

When launching reports, she won't wear jewellery, except for unobtrusive earrings (and on a daring day, a small brooch), because it might distract from her message.

She never deviates from sober suits and Presbyterian blouses, noting, with a hint of mischief, that when Brenda Fricker played her in the film Omagh, "She wore her blouses open at the neck, whereas mine are closed or have only one button undone." An admirer remarks: "Nuala has a sense of humour - albeit in a schoolmistressy way."

He recalls her warning a group of young police recruits in teacherly tones: "Now, I'm here to support you but, if you break the law, I won't hesitate to arrest you." The idea of the prim and proper ombudsman arriving on their doorstep to arrest them at 6am raised smiles.

No one can ever claim she's soft on paramilitaries. As a University of Ulster law lecturer, she suffered a miscarriage when an IRA bomb aimed at Lord Chief Justice John McDermott exploded in a lecture theatre in 1976. O'Loan had been meant to sit beside him but was called away at the last minute. The chair she would have sat on was blown to smithereens.

Unionists dismiss her as "the wife of an SDLP politician". Her husband Declan sits on Ballymena Council but O'Loan has always been her own woman, joining the North's Police Authority when SDLP policy opposed it, hence the 'safe pair of hands' reputation. "When Nuala was appointed ombudsman, I think she didn't realise how bad policing had been, " says a nationalist source.

"But she's a very moral, principled woman and, when she discovered wrongs, she was never going to back off. She didn't set out to be radical.

She's just committed to the truth." Neither is she a political broker. The release of the McCord report so near the ardfheis was bad timing for Sinn Féin. Had the British government asked her to delay publication to help the party, she would have told them to get stuffed.

She was born in Hertfordshire, the eldest of eight.

Her father, a solicitor's clerk from Dublin, died when she was 13.

Escape from poverty came via a scholarship to a boarding school. She met Declan at a dance in King's College Catholic chaplaincy, London, when they were both students. Friends describe them as a "very serious but very happy couple".

In their early married life, they decided they "wanted an adventure". They gave up their jobs, rented out their home, and set off for the African bush. They already had a baby son and O'Loan was seven months pregnant and unable to be vaccinated against cholera or typhoid.

She dismissed warnings of health risks with a brisk, "Women have babies in the bush all the time." She gave birth in a dangerously primitive hospital and developed malaria. But she fell in love with Africa and never regretted her time there:

"You have to leave your comfort zone, do things you never thought you would. Otherwise, you become smug and useless."

She adores her five sons but misses the conversations she might have had with a daughter. Her ferocious protectiveness of her children led to "the cappuccino confrontation" with Ian Paisley jnr in a coffee shop last year when O'Loan approached the DUP justice spokesman about remarks he had previously allegedly made about her family. Two sons have been beaten by loyalists and friends confide that O'Loan worries about them, particularly when in Ballymena, where Michael McIlveen was beaten to death last year. They also say her demonisation by some unionist politicians caused her to fear for her own safety in the early days after taking up her post - Rosemary Nelson, an outspoken Catholic lawyer, was shot dead by loyalists in 1999.

O'Loan's consistent objectivity has enabled her to overcome allegations of bias - Protestants now bring more complaints to her than Catholics, 47% to 35%.

Her reputation as the people's champion means she receives complaints about traffic wardens and dentists as well as police. Raspberry and vanilla tea helps her through 15-hour days. At home, she relaxes by reading the Bible, religious books and trashy novels.

Criticism that, as a woman, she would never understand security matters encouraged her to go on the beat with police. She was spotted driving around in Land Rovers in the middle of the night.

She has an excellent relationship with PSNI chief constable Hugh Orde.

In 2002, the British government unsuccessfully tried, in draft legislation, to clip her powers. A US government representative was horrified to hear a ministry of defence official later remark: "Did we get away with that thing with O'Loan?"

The shame is that, despite the McCord report, those in senior British government and police circles, responsible for collusion, will escape justice because other powerful figures in public life lack O'Loan's commitment. She's not a revolutionary, just a very honest reformer - with guts.

C.V.

Name: Nuala O'Loan
Born: 20 December 1951, Hertfordshire, England
Job: the North's police ombudsman
Marital status: married to Declan, SDLP councillor. They have five sons
In the news because: She launched a damning report on police collusion