The Star Sunday source said: "Murphy spent two years compiling the report and spoke to everyone involved in the case. He conducted it in a fair but thorough way and didn't leave any stone unturned.

 "He met members of the Ludlow family and talked to them about their concerns. He reported without fear or favour, but nothing was done about what he found."

 The report is expected to  reveal that the initial Garda investigation into Ludlow's murder petered out after weeks, because security forces, especially the RUC, were not co-operative, and later new leads were not followed up.

Inquest

 He also criticises the way the Ludlow family were treated at the inquest. Family members only got 45 minutes notice that the inquest was on and were unable to attend. It concluded without them.

 The source said: "There was no good  reason why the family weren't given notice about the inquest. They were badly treated and some former officers will have to take the blame or that."

 Theories about a top-level cover-up within the gardai in relation to the murder have dogged the force for years.

 Relatives of Mr Ludlow met with Mr Justice Barron this week to find out about progress on the former judge's inquiry into the murder.

 Justice Barron, who published his report into the Dublin and Monaghan bombings earlier this year, said the Ludlow findings would be ready by the end of September.

 Louth County coroner Ronan Maguire, has spent two years pleading with Garda authorities for the report which he believes will answer many questions about the investigation.

 He was asked to a meeting at Dundalk Garda station last month and was met by two top ranking members of the force - one from Dundalk and one from HQ at the Phoenix Park.

 Mr Maguire told Star Sunday: " The meeting was polite and god natured. They told me that they would think about handing over the report and I have got word that they have agreed to my request.

 "I have not seen it yet, but I understand that the names of chief suspects will be blanked out. But I think it will be of some assistance to the inquest.

 "The purpose of an inquest is not to blame or exonerate anyone connected to the death, but it is good to have as many details as possible," he sad.

 Mr Maguire will decide within the next  two weeks whether to call former Superintendent Murphy as a witness at the inquest. Former State pathologist Dr John Harbison, who carried out the post-mortem, is also expected to give evidence.

 Rumours

Since the murder in May 1976, controversy has surrounded the garda investigation. The family claim Dundalk gardai spread rumours that the dead man was shot by the IRA for being an informer.

 Theories have abounded that there was high-level suppression of the investigation within garda headquarters because of the politically sensitive circumstances surrounding it.

 It is believed that Ludlow, a bachelor, was walking home from a pub on the main Newry Road to the north of Dundalk, when he was bundled into a car by loyalists, two of whom, it has been alleged, were officers in the British Army's Ulster Defence Regiment and loyalist terror gang, the UVF.

 He was not involved in any political or subversive movement and one theory suggests that he was murdered by the gang because they mistook him for a high level republican figure living in Dundalk at the time.

 In 1987, Paul Hosking, one of the men who was in the car on the night Ludlow was murdered, went to the RUC Special Branch and gave them a full account of the murder.

 He said he was 19 at the time and was drinking in a bar in Co. Down when two UDR men and a third loyalist came in. They went for a spin and headed, armed with handguns, over the border.

 They stopped in a pub in Omeath in North Louth and drank four pints each. They then headed for Dundalk. On the way into the town, they spotted Ludlow hitching.

 Bangs

 Hosking claimed Ludlow got in and they stopped in a laneway. He got out to urinate, when he heard loud bangs and saw one of the gang shooting Ludlow.

 The UDR men helped the killer dump the body in the laneway before driving home.

 In 1998, four men, including Hosking, were arrested and taken to Castlereagh Holding centre for questioning.

 There have been allegations that police officers in the north had an eyewitness to the shooting.

 The men were questioned and released and a file was sent to the Northern DPP but no charges were brought.

 Ludlow's nephew, Jimmy Sharkey said: "I hope that the Murphy report will shed some light on the way the gardai conducted their investigation into my uncle's death."