Police knew the identities of those who killed solicitor Rosemary Nelson shortly after her murder, but did not have advance intelligence which could have saved her life, an inquiry has heard.

Former RUC chief constable Sir Ronnie Flanagan yesterday gave a third and final day of evidence at the public inquiry probing allegations of security force wrongdoing over the lawyer’s murder in a loyalist car bomb in March 1999.

No-one has been convicted of her killing, but Sir Ronnie revealed that at an early stage in the murder hunt police knew the names of those who planted the device, as well as the identity of the bomb-maker.

In a statement handed to the inquiry, Sir Ronnie said: “I do recall being told that (names withheld) carried out the murder and that (name withheld) had made the bomb.

“This was at an early stage in the investigation, although I cannot specifically recall when.

“This was put to me on the basis that Special Branch were confident in this view, it was not a question that these three were mere suspects.”

I personally never dreamt for a moment she was at risk

He said he believed the information was handed to former Norfolk Deputy Chief Constable Colin Port, who was drafted in to lead an investigating team made up of police from England and RUC officers.

Sir Ronnie said the Port team was promised full access to police files but said there were tensions with Special Branch when Mr Port sought the names of loyalist informants in the Lurgan area. Human rights groups had raised concerns for Mrs Nelson’s safety after she claimed police officers had come to associate her with the alleged crimes of republican clients and had threatened her life.

Her murder was claimed by the Red Hand Defenders, but this was considered to be a cover name and Sir Ronnie said the Loyalist Volunteer Force was thought to be at the centre of the plot. He said Mrs Nelson had been murdered by thugs and cowards who were determined to kill, but that, in the absence of intelligence of a direct threat, police could not have saved the mother-of-three.

The former police chief recounted how the Troubles had seen more than 300 RUC officers murdered and thousands injured. He added: “Sadly, when a number of my friends died in the way that Rosemary Nelson died and it was not possible to protect their lives, even if things were done differently, it is my sad conclusion it would not have saved Mrs Nelson’s life.”

In assessing risk to the solicitor, he had endorsed the decision to have police monitor Mrs Nelson’s home and business as a precaution, but in the absence of a specific threat, it was decided not to have a crime prevention officer speak to her.

Sir Ronnie said: “I personally never dreamt for a moment she was at risk of what subsequently happened.”

Asked if he might have done anything differently, he added: “I would have made sure Mrs Nelson was seen personally, was given advice.”

But he said such a move could not have ensured her safety and, rejecting claims that the episode was an intelligence failure, he said: “Intelligence is not infallible.”

The inquiry heard evidence on allegations by some police officers that Mrs Nelson was having an affair with Lurgan republican Colin Duffy, who police believed was a leading IRA member. Other witnesses close to Mrs Nelson have dismissed the claims as an attempt to discredit her.

A security force document requested permission to bug a house owned by Mrs Nelson, but rented by Mr Duffy, who was the target of the surveillance.

It stated as a fact that Mrs Nelson was having an affair with Mr Duffy and also referred to “false alibis that PIRA, assisted by their solicitor Rosemary Nelson” were preparing for two terrorist suspects.

Sir Ronnie said he viewed the alleged affair as rumour, which he did not disseminate. The inquiry heard that, after Mr Port came to head the murder hunt, his terms of reference promised access to all RUC files, but there was concern from Special Branch over a request for the names of loyalist informants. Sir Ronnie said he was aware of friction, but said RUC officers had acted in good faith.