The owner of Ireland's longest-established lie detector service has said she is prepared to conduct a polygraph analysis on Ian Bailey.
Mr Bailey has spoken recently of his desire to undergo a polygraph test on camera to prove he didn’t kill Sophie Toscan du Plantier.
Despite being the self-confessed chief suspect for the unsolved murder of Ms Toscan du Plantier in west Cork in December 1996, Mr Bailey has always maintained his innocence and has never been charged with the killing here in Ireland.
Just last month the 64-year-old claimed he had informed movie director Jim Sheridan he was willing to be filmed taking a lie detector test “to prove to the whole world I am innocent”, as part of the Dublin filmmaker's recently-released documentary on the murder mystery.
But the test didn't proceed, as Sheridan opted not to take him up on his offer of using a polygraph for inclusion in the hit Sky documentary Murder at the Cottage: The Search For Justice For Sophie.
However, Sian Devine, who runs Dublin-based Lie Detector Ltd, said she would be willing to conduct a specially-tailored polygraph probe on Bailey.
She said: "Ian Bailey's circumstances are characteristic of why many people opt to take polygraph tests - they simply feel that they have no other way to prove they are being truthful.
"The polygraph is often referred to as a 'lie detector', and is a term that most people recognise. However, it is not detecting lies and it would be more accurate to describe it as a truth verifier.
"When the person being tested is not being truthful, an involuntary physiological response, associated with the deception, occurs. If this response takes place when the examinee is answering the questions pertaining to the reason the test is being conducted, they will fail the test. But if this response does not occur, they will pass the test.”
Ms Devine said however that a polygraph test has its limits.
"A polygraph test isn't infallible, but it's fairly conclusive and in this case we would conduct what's called a single issue polygraph test, which would have a narrow focus, with questions all relating to one single issue,” she said.
"The questions would not be emotive or be designed to over-stimulate the examinee. Using a word like 'kill', for example, could be emotive and should be avoided.
"The wider you make the issue and the more questions you ask, the less accurate the test becomes. But this way the results would be up to 97pc accurate."
As her polygraph machine is portable, Ms Devine said she would be prepared to travel to a location agreed by herself and English-born Mr Bailey. She also said the polygraph probe would take up to two-and-a-half hours in total, and would consist of a pre-test interview, the actual test itself, and then a post-test interview.
She added: "Ian Bailey is in a position whereby the DPP concluded on more than one occasion that there was not enough evidence to charge him. However, for many people this did not clear him, whilst many others believe he is innocent, and some just don't know what to believe. Ian Bailey may feel he has nothing to lose and potentially much to gain by taking a polygraph test."
When asked if he would be willing to undergo a polygraph probe with Lie Detector Ltd, Manchester-born Mr Bailey said: "It's really not my top priority at the moment. I've got other things I need to deal with. I don't want to make any further comment at the moment."
Mr Bailey was arrested twice by gardaí in the months following French filmmaker Sophie Toscan du Plantier’s death, but was never charged.
Despite that, French authorities launched their own prosecution against Mr Bailey in 2019, and convicted him in absence for the killing.
A Paris court sentenced him to 25 years in prison.