A FORMER garda shot dead in his remote rural home had been questioned over his neighbour's disappearance 18 months ago.
The body of John Kerins was discovered in the large detached two-storey house in the townland of Cornaveagh, near Bailieborough, Co Cavan, shortly after midday.
It is understood the victim was medically discharged from An Garda Siochana several years ago and moved to the area.
He had served as a senior detective in a number of specialist units in the force throughout his career.
A murder investigation is expected to be launched by detectives after the scene is forensically examined.
Mr Kerins, who was in his late 40s, was arrested and questioned by gardai when his neighbour Gerard Daly vanished in June 2010.
The missing man, who turned 44 on Wednesday, was a dog breeder from Dublin and is feared murdered.
The pair were said to be planning to go into business together, breeding security dogs for business, before Mr Daly's disappearance.
Mr Kerins was also recently arrested and questioned over the seizure of stolen goods.
One Garda source said the dead man could have been targeted by associates he became involved with after leaving the force.
"For a garda he had a very chequered past," said a local man who knew the victim.
Mr Kerins, a father, separated from his wife last year and was living alone at the house which is 7km from Bailieborough off the main road to Cootehill.
The victim was said to have become dishevelled over the last 18 months, growing his hair and beard long.
It is understood his body was found by a member of his family who called to the home.
A garda spokesman said the area has been sealed off and that the office of the State Pathologist has been informed.
A post-mortem examination is due to be held tomorrow.
Meanwhile, Mr Daly's family have made several appeals urging any person, even with the smallest piece of information, to make it known to the gardai.
He was reported missing on June 29 2010.
There was no sign of a struggle or a disturbance at his home and the only things missing are his mobile phone and the keys to his van.
Investigations into his whereabouts included probes in the Bailieborough area, as well as the border region, England, Jersey and Malta.
Gardai have also been working closely with the PSNI, Interpol and Europol and detectives from the National Bureau of Criminal Investigation to try to solve the mystery over his disappearance.