Private investigators and detectives across the world have contacted the family of Sophie Toscan du Plantier offering to help solve the murder of the French woman in West Cork 25 years ago.
Jean-Pierre Gazeau also backed calls for a fresh garda investigation into the killing.
Former chief suspect Ian Bailey recently sought the same in correspondence with Garda Commissioner Drew Harris.
Mr Harris is considering the request, but has not committed to ordering a review.
Mr Gazeau, a French physicist and mathematician, set up the Association for the Truth of the Murder of Sophie Toscan du Plantier in the aftermath of his niece’s killing.
“Because of all the publicity around the documentaries, I’ve had people from all over the world, private investigators and detectives, emailing the association from places like Australia, Brazil, Canada, Poland. People offering their help,” Mr Gazeau said.
“The media coverage is relentless, but I see it as a good thing. We were expecting huge media interest again, because the Sky and Netflix documentaries reached so many people all over the world.
“Sophie is not forgotten, she is in the spirit of the people.
“We are fighting for truth and justice. We want to reach the truth. It was a terrible murder. Why should we forever stay in ignorance about what happened and why it happened?”
Mr Gazeau said he “fully supported” Mr Bailey’s calls for a fresh garda investigation, “and I don’t usually agree with anything that man says”.
Ms Toscan du Plantier was found beaten to death outside her holiday home near Toormore, Co Cork, on December 23, 1996.
Gardaí identified Mr Bailey, then a journalist, as a suspect, but he has repeatedly and vehemently denied any involvement in the murder.
The DPP has twice ruled he should not be charged in connection with the film-maker’s death.
It remains one of Ireland’s most notorious murders, and the investigation has seen numerous twists and turns.
The latest development came after director Jim Sheridan contacted gardaí to say former Schull shopkeeper Marie Farrell gave him important information while he was making his documentary, Murder at the Cottage: The Search for Justice for Sophie.
Ms Farrell, who previously put Mr Bailey near the scene of the murder but later withdrew her statement, now claims she saw a known associate of Ms Toscan du Plantier’s husband, Daniel, in West Cork at the time of the murder.
Detectives have taken a statement from Ms Farrell, in which she identified a man she saw near Ms Toscan du Plantier’s house on the night of the murder as being an associate of film producer Daniel du Plantier, who died in 2003.
This weekend, Mr Gazeau dismissed the shopkeeper’s latest claim.
“It is unbelievable what Marie Farrell is now saying. Also, she said it before and it was investigated before, so it is nothing new. I am very sceptical of this story. It was already analysed,” he said.
“But I fully support the idea of a new garda cold case investigation into the murder. It is so unfair that this case has not been solved yet.
“Ian Bailey was convicted in France. For me, Ian Bailey is guilty, and that was clear from the beginning. It would be great if Ian Bailey was brought to France to answer all of the questions in a retrial. It has been very disappointing that Ireland has denied his extradition.
“But a cold case review, that could be one way to get out of this saga after 25 years.”
The High Court rejected a third attempt last October by the French to extradite Mr Bailey to stand trial.
Undeterred by the Irish courts’ refusal to hand him over, the French opted to try him in his absence in Paris, and he was convicted of murder in May 2019, in a process he described as “a farce”. He was sentenced to 25 years in a French prison.
Should Mr Bailey ever set foot in France, he would be arrested and face a retrial.
Mr Gazeau said he is aware of some of the “outlandish” things Mr Bailey has been saying in recent media interviews. He also said he was aware of the surge in so-called murder tourism in West Cork in the wake of the documentaries.
“I have heard about all of this, people visiting Sophie’s house and wanting to meet Ian Bailey. He talks a lot. He plays a game with the media,” he said.
“I have read some of the stories of what he is saying. He said Princess Diana was attracted to him, I believe, and that big-bosomed women he met on the internet want to go on dates with him since his break-up with [former partner] Jules Thomas.
“Ian Bailey plays a game with the media with all his talk. I would just invite him to France so he can answer some of the questions the judge has.”
Ms Toscan du Plantier’s parents, Georges and Marguerite Bouniol, are in their 90s and are being “protected” from much of the media coverage of the case.
Her son, Pierre-Louis Baudey, who was 15 when she was murdered, is handling the coverage well, Mr Gazeau said.
“Sophie’s mother is my sister. She and Georges are being protected from the media coverage. They deserve a peaceful life now. They do not want to know about all that is being said,” he said.
“Pierre-Louis, I think he deals with it all very well, but at certain moments it must be very difficult. It is a sort of trauma, what has happened to him, losing his mother at that age.”