A former Garda inspector pushed for a harassment case against Ian Bailey despite concerns it would be difficult to prosecute, he has told a court.
Retired Vincent Duggan, who was stationed at Bantry, Co Cork, said he was told to investigate a number of allegations by witness Marie Farrell in 1997.
Mr Bailey, 57, an Englishman who moved to West Cork more than 23 years ago, is suing the State after being arrested twice over the killing of a French film producer.
Sophie Toscan du Plantier, 39, was found beaten to death outside her home in West Cork on December 23, 1996.
Mr Bailey denies any involvement in the death and was never charged.
Dublin's High Court heard Ms Farrell alleged she had been approached by Mr Bailey at her shop in Schull on June 30 1997 and was left most upset by the encounter.
Mr Duggan said he went to the village to speak with Mr Bailey about the claims, but the law graduate and former journalist said he had just called into the shop for a coffee.
The retired inspector said Mr Bailey agreed that Ms Farrell be left in peace.
Under cross-examination, he said he was not told at the time the encounter in the shop was being recorded by gardai, in what Mr Bailey's legal team described as a staged event.
Later that year, on December 19 Ms Farrell contacted gardai again complaining she had received an upsetting phone call that day from Mr Bailey.
Mr Duggan said he was instructed to take a statement from her and prepare a file on the incidents.
On meeting Mr Bailey to put the allegations to him, he was told that he was in Bantry the day of the alleged phone call and never made any calls.
A garda sergeant in Bantry confirmed seeing Mr Bailey in the town on the day and no telephone call could be traced, he told the court.
Mr Duggan said in his file on the harassment allegations, he recommended "with a caveat" the Director of Public Prosecutions proceed with a case against Mr Bailey.
The decision was taken based on the "totality" of the allegations and it was not unusual to express views, doubts and possible difficulties when recommending prosecution, he said.
In the event, the public prosecutor decided not to go ahead with any proceedings.
Judge John Hedigan told the jury there were 32 witnesses left in the long-running case.
"I think there's a bit of light at the end of the tunnel, I can see the end approaching," he said.
It is expected the hearings could be completed by the end of March or beginning of April.