Ian Bailey was arrested on suspicion of drink driving in West Cork last night.
Mr Bailey was arrested on Sunday evening by Gardai in Schull. However, he said he was later released without charge after he passed the intoxilyzer test in Bantry Garda Station.
The writer, 62, was recently found guilty in absentia by a French court for the murder of Sophie Toscan du Plantier.
Ms Toscan du Plantier was found dead near her holiday home in Schull in December 1996.
Mr Bailey has always denied any involvement in her death.
Gardaí confirmed they arrested a man in his 60s in relation to a drink driving offence on Sunday evening in Schull but did not confirm that it was Mr Bailey.
In a statement, Gardaí said an individual was detained at Bantry Garda Station overnight and investigations were ongoing.