Ian Bailey, who was questioned in connection with the death of Sophie Toscan du Plantier in West Cork in 1996, has been indicted in France for her murder.
Mr Bailey has been served with papers by gardaí, on behalf of the French authorities.
Mr Bailey's extradition to France has been refused by the courts in Ireland because of the lack of evidence connecting him to Ms Toscan du Plantier's murder.
He is now likely to be tried in France in his absence.
RTÉ News understands the serving of papers on Mr Bailey is the first formal communication he has had with French authorities.