A court has heard the murder of Rosemary Nelson could have been averted if police had responded more quickly to death threats against her.

Six months before she was killed by a loyalist booby-trap car bomb, the Catholic solicitor was warned of a plot to murder her.

One letter sent to her declared: "We have you in our sights you republican bastard, we will teach you a lesson RIP."

Rosemary Nelson: A high profile solicitor

The Catholic mother-of-three died in a booby-trap car bomb near her home in Lurgan, County Armagh on 15 March 1999.

A human rights group has begun an action at the High Court in Belfast to gain access to police investigation files.

Its legal team said that the delay in examining the threats may have been fatal.

Seamus Treacy QC said: "We submit the possibility that if these investigative steps had been carried out at the appropriate time Mrs Nelson might have been saved."

Former Security minister Adam Ingram was sent the letter in August 1998 by the Belfast-based Committee on the Administration of Justice (CAJ), the court was told.

The group was told within weeks that the Northern Ireland Office had passed the documents on to the then-chief constable Sir Ronnie Flanagan.

A splinter loyalist group, the Red Hand Defenders, said it carried out the murder.

The Red Hand Defenders is a cover name which has been used in the past by the Ulster Defence Association and Loyalist Volunteer Force.

Complaints

One week after the murder, detectives asked the CAJ for original copies of the death threat letter and another sinister note which referred to Mrs Nelson, the court was told.

Mr Treacy said police should have conducted forensic tests on the documents that may have led them to the killers when they were first alerted six months earlier.

"This was basic investigative work, but the RUC in this case didn't come looking for the originals until after she was murdered," Mr Treacy said.

"It's not as if there could have been any doubt about the significance of the documents."

The security forces have insisted there was no intelligence to suggest Mrs Nelson was being targeted by loyalists.

The CAJ has been denied access to papers on the case.

Representatives complained to Northern Ireland Police Ombudsman Nuala O'Loan, but Mr Treacy said she had also turned down its requests for documents.

Mr Justice Kerr, who is hearing the judicial review, was expected to reserve judgment.

Mrs Nelson was a high profile solicitor, whose clients included the nationalist Garvaghy Road Residents Coalition.