Gardaí investigating the murder of Ashling Murphy have arrested a second man in connection with the 23-year-old's death.
The second man, aged in his 30s, is currently detained in the Eastern Region, Gardaí said, under provision of Section 30 of the Offences Against the State Act 1939 as amended.
He is being questioned in relation to potential withholding of information contrary to the Offences Against the State (Amendment) Act 1998.
Gardaí confirmed officers are continuing to question a 31-year-old man arrested on Tuesday on suspicion of Ms Murphy's murder.
The suspect is being held at Tullamore Garda station under provisions of Section 4 of the Criminal Justice Act 1984.
He was arrested after being discharged from a Dublin hospital earlier on Tuesday, where he had received treatment for serious injuries which gave medical staff cause for suspicion, leading them to contact Gardaí.
The man was arrested once he was deemed physically and mentally well enough to be discharged and questioned. The period for which he can be questioned is due to expire on Wednesday evening.
Ms Murphy was killed on Wednesday, January 12th at approximately 4pm while out for a run along the canal bank at Cappincur, Tullamore in Co Offaly.
Her funeral took place on Tuesday, with Gardaí arresting the suspect around the same time.
According to The Irish Times, Gardaí believe the person who killed Ms Murphy was carrying a weapon which they later discarded. Officers are continuing efforts to locate any such weapon, with searches expected to continue for several days.
The crime scene along the Grand Canal at Cappincur remains sealed off.