Ian Bailey's solicitor in West Cork has said he is saddened by his death as it means he can never lift the "dark shadow" cast by the Sophie Toscan du Planter case.
Ray Hennessy said he was one of the few people who seemed to believe Mr Bailey was innocent of Ms Du Plantier's murder.
Now retired, Mr Hennessy represented Mr Bailey before the District Court in West Cork on a recent drug-driving prosecution, which led to a conviction and which is currently on appeal before the circuit court.
However, Mr Hennessy said he saw Mr Bailey just a week ago and recalled that on New Year's Eve Mr Bailey had called him to ask him whether he wanted to accompany him to a Phil Coulter show at Bantry's Maritime Hotel, as he had secured a spare ticket.
"I am very sorry to hear that he has passed away without having the whole issue resolved because it was obviously playing on his mind big time," Mr Hennessy said, speaking about the long-running controversy over the Du Plantier murder.
Mr Bailey had consistently denied any involvement in Ms Du Planter's death in December 1996, in what is one of the country's highest profile unsolved cases. However, he was convicted in absentia by a French court in 2019.
According to Mr Hennessy: "I think the whole country had him convicted and I was one of the few people who believed he was innocent."
Mr Hennessy said for Mr Bailey, the situation had resulted in a "dark shadow hanging over him".
In recent years the Du Plantier case has been the subject of a hugely-successful West Cork podcast series as well as the focus of two documentaries, one by acclaimed film director Jim Sheridan, the other by Netflix.
However, Mr Hennessy said Mr Bailey's involvement "did not work in his favour" as "they didn't change anyone's opinions".
Mr Hennessy said the conviction of his former client in the French courts had taken a toll, particularly on his physical health.
"I thought he remained pretty strong for what he had endured," he said.
"The biggest thing that affected him was when he departed from Jules," he added, referring to Mr Bailey's former long-time partner, Jules Thomas, who broke off the relationship in recent years.
Mr Hennessy said Mr Bailey had courted publicity; "he wanted frontline all the time", but that he had also often spoken about his treatment by gardaí during the course of the investigation into the Du Plantier murder.
"He was quite a character," Mr Hennessy said.
Elsewhere in West Cork the early reaction to news of Mr Bailey's death was relatively muted. On Facebook, hairdresser Grainne Kollins in Skibbereen posted 'RIP to my buddy" Ian Bailey, alongside two TikTok clips featuring him.
In the first clip, Mr Bailey said he was getting his "pre-Christmas re-beautification from the lovely Grainne", with the clips showing the pair wishing everyone a happy Christmas. Among others paying tribute on social media was Donegal County Council representative Frank McBrearty Jnr, who said he was sad to hear the news of Mr Bailey's passing, adding: "Another miscarriage of justice case that the State should have had a statutory public inquiry into".