Journalist Ian Bailey contemplated suicide due to "a deep sense of despair and hopelessness" after being twice arrested following the murder of French film-maker Sophie Toscan du Plantier.
The Dublin high court was told of his anxiety when he was arrested for the second time in January 1998, the day of his 41st birthday.
Bailey said a police officer told him there was "a nice little cell waiting for you in Mountjoy". The first arrest was almost a year earlier, in February 1997.
He said said police insisted "everybody knew" he had killed du Plantier - whose body was found in west Cork on 23 December 1996.
Bailey experienced sleep disturbance and weight loss and his mind was so troubled after the first arrest he was unable to concentrate and could not get work as a journalist.
He told the court that events in the 18 years since the murder affected him and his partner Jules Thomas, their families and the community, and this was "still going on".
"I don't think I handled it very well in the early days," he told his lawyer Martin Giblin. "I got to the stage where I was contemplating the possibility of suicide."
Mr Bailey was continuing his evidence in his action for damages against the Ireland's police commissioner and the state.
He alleges he was wrongfully arrested in connection with the murder of du Plantier and that police conspired to manufacture evidence against him.
The defendants deny all the claims in the action, which continues before a jury.
Bailey, a British citizen who has lived in west Cork for 23 years, was formerly a crime reporter in Manchester.
Sources: Irish Times/Irish Independent
