Irish police are continuing to question two men in the investigation into the murder of 23-year-old teacher Ashling Murphy.
It comes after gardai arrested a second man, aged in his 30s, on Wednesday.
The man is being questioned in relation to the potential withholding of information and is being held at a garda station in the east of the country.
Another man remains in custody on suspicion of murdering Ms Murphy in Tullamore, Co Offaly.
The man, who is aged in his 30s, was arrested on Tuesday in Co Offaly.
Irish police said the man is still being questioned at Tullamore Garda station.
The law allows for murders suspects to be questioned for 24 hours, which means the man must be charged or released within the next few hours.
The arrest was made after police renewed an appeal for information, saying “significant progress” had been made with their investigation.
The body of Ms Murphy, a talented musician and teacher, was found on the banks of the Grand Canal in Tullamore last Wednesday.
A crowd of around 40 people walked along the canal on Wednesday, close to where her body was found, to mark one week since her murder.
On Tuesday, large crowds gathered in the village of Mountbolus and outside St Brigid’s Church, where her funeral was held.
Mourners included Irish president Michael D Higgins and Irish premier Micheal Martin.
Vigils have been held across Ireland and the world to remember Ms Murphy and to call for a change in tackling gender-based violence.