Ian Bailey claims Gardai told him paramilitaries would kill him with a bullet to the back of the head if he did not confess to the murder of French beauty Sophie Toscan du Plantier.
He makes the allegation in the second episode of his new podcast to be broadcast this week, Paradise Found, Paradise Lost.
He said he was given the warning by a senior officer who he named when he was first arrested over the shocking Christmas 1996 killing.
READ MORE - Ian Bailey opens up about now-ended relationship with Jules Thomas and claims her kids were jealous of him
He also alleged that his former partner Jules Thomas was told he had confessed to the crime when he hadn't.
During the lengthy podcast, the English journalist says Sophie did not arrive in Ireland alone for that final fatal trip to west Cork on December 20 that year.
He names a witness who met her getting petrol and confirmed there was another man with her. A second witness believes a man was following her on the last day she was seen alive.
Bailey said: "She booked two return tickets - one for Monday, Dec 22 and the other for Christmas Eve.
"A number of Irish passengers noted she appeared to be travelling alone with two suitcases and hand luggage. What appeared to be quite a lot of luggage for a weekend retreat.
"One theory was that she was planning to leave France and her husband and to set up a full-time home in Ireland and was moving possessions. She'd previously told one west Cork inhabitant she wanted to get away from her life in France and start again in Ireland.
"She stopped for petrol in Skibbereen and the pump attendant Mr Sean Murray gave a very exact statement that she had a male passenger with her. This was the first of several unconfirmed sightings of an unidentified male.
"What is clear is Sophie made other stops including the village of Ballydehob but significantly there were no sightings of her with a male companion.
"What is clear from statements taken from French friends, Madame du Plantier did not want to travel alone. She had previously asked two friends Agnes Thomas and her aunt Marie to accompany her but neither were free, it was Christmas.
"On Saturday, December 21 Sophie drove the six miles into Schull village to do some shopping . At the west end of the village she went into a clothing store run by Mrs Maria Farrell and her husband.
"Significantly Mrs Farrell reported at the time Madame Du Plantier was in her shop she observed a man wearing a dark coat and a French-style beret across the road outside the shop.
"She further stated that this man who was about five foot eight or thereabouts had subsequently followed the French visitor up the road to her car. "
Ian Bailey revealed on the night she was killed Sophie had twice called her husband Daniel in France at his chateau.
The following morning Sophie's body was found by her neighbour Shirley Foster on the lane to her house.
The gate at the scene was wide open with the handprints of the killer on it. The gates subsequently disappeared.
Mr Bailey, 64, said the Sophie case is the greatest murder-mystery in Ireland's history and has affected the otherwise good name of the Garda Siochana.
He alleges that in late January he received a call from a senior Garda who, he claimed, came out to his house and "asked me if I played poker. His last words to me were he was going to place me close to the murder scene in the early hours of Monday, December 23.
"I said that's nonsense and he said we'll see. It was a chilling response and would foretell what was subsequently going to happen to me.
"On Monday, February, 11 , 1997 I was targeted by the Irish police force, An Garda Siochana, arrested, handcuffed, falsely accused and then publicly rebranded as the prime suspect.
"At the time of putting this podcast to bed there is currently a cold case review underway. I am offering my full cooperation to the reinvestigation but at the time of this recording I have not been contacted.
"My hope and prayer is that the true identity of the killer can be established and if not at least it is acknowledged that I had nothing to do with this terrible crime.
"On New Year's Eve a Garda detective took hair and fingerprint samples from Jules and I.
"The false story that I was spotted washing welling boots near the murder scene had spread among the population.
"Two detectives came to my office and cautioned me. I was taken aback. I was handcuffed and forced into the back of the patrol car. Little did I know that I was at the beginning of what was to become a 26-year nightmare.
"I remember Jules shouting at them you are making a big mistake.
"One of the detectives kept jabbing me and said I should confess, the accusations were unrelenting.
"The detective driving the car said 'even if we don't pin this on you Bailey, you are finished in Ireland. You will be found dead in a ditch with a bullet in the back of your head'.
"I said that sounds very menacing to me. And his response was 'It won't be us that do that' which I took to mean a clear reference to paramilitarism.
"I was photographed being walked into the barracks in handcuffs.
"The interrogation was not an interview but just a tirade of unfounded accusations. You did it, you did it, you did it."
READ NEXT:
- House next to where Sophie Toscan Du Plantier was murdered for sale for second time in two years
- Ian Bailey given more time to find new home after eviction notice but still cannot find a house
Get news updates direct to your inbox by signing up to our daily newsletter here
