A BRUTAL Greenock murderer's death whilst serving life for killing his neighbour was due to natural causes, a sheriff has determined.

Graeme McLaren used a walking stick to inflict horrific internal injuries on 64-year-old James Small, who died in agony in his east end flat.

McLaren, 51, had been sentenced to a minimum of 20 years in December 2013 but died in hospital last September of cirrhosis and carcinoma of the liver.

Sheriff Douglas Brown, who presided over a fatal accident inquiry (FAI) into McLaren's death, has now concluded that his demise was purely down to the state of his health.

Murder victim Mr Small died in huge distress four days after McLaren had attacked him at his Weir Street home on June 5 in 2013.

McLaren went on to boast and joke about the killing to several people and even showed one shocked woman the bloodstained weapon.

At a trial at the High Court in Glasgow he then attempted to smear Mr Small's name with an utterly false sex attack allegation.

A jury unanimously found McLaren guilty following six days of harrowing evidence, and judge Lady Rae told him at sentencing that he he had convicted of a 'brutal and depraved act on an elderly man'.

She added: "Not satisfied with causing him horrific injuries, which you inflicted in a demeaning way, you then placed him in fear with a wholly false allegation that you made up.

"Because of his embarrassment he failed to get medical help and died alone.

"He must have suffered excruciating pain."

FAIs are mandatory when prisoners die in custody.

In his written determination on McLaren's death, Sheriff Brown states: "Where preliminary investigation by the procurator fiscal establishes that a death...was due to natural causes and the court is satisfied that the circumstances do not give rise to any concern, the evidence at the inquiry may be brief and unchallenged. That was the situation here.

"In particular Mr McLaren's sister, speaking on behalf of the family, had confirmed that they had no concerns about his treatment by prison staff and medical staff and, more than that, had expressed appreciation for the medical care he received."

The sheriff noted that McLaren — who had been coughing up blood — had a 'lengthy history of drug abuse, involving heroin and cannabis'.

A joint minute of agreement regarding the circumstances of McLaren's death at Wishaw General Hospital on September 4 last year was submitted to the inquiry last month.