A man has been arrested in connection with the investigation into a bomb threat made on the home of the Taoiseach six weeks ago.
The man, who is in custody for unrelated offences, was arrested this morning.
Detectives secured a Section 42 warrant which allows gardaí to remove an inmate from a prison as part of a criminal investigation.
The 53-year-old was taken to a garda station and is being detained under Section 4 of the Criminal Justice Act.
He can be questioned for up to 24 hours.
The investigation commenced after a bomb threat on the home of Taoiseach Simon Harris and his family was made in a phone call to the Samaritans helpline at around 6pm on 26 June.
Gardaí searched the house but no device was found.
It is the third garda investigation into threats and harassment of the Taoiseach and his family in the last three months.
Gardaí are also investigating a threat made against the Taoiseach and his family last weekend.
That threat, which was posted on Instagram, refers to a weapon and threatens violence against Mr Harris and his wife and children.
The threat remained online for at least two days and was widely shared and circulated before Instagram removed it.
The Taoiseach said he would not be deterred from doing his job and warned social media companies that regulations are expected to be in place by the end of the year and that Ireland will "hit where it hurts" if they fail to take responsibility for threatening and harmful content on their platforms.
Anti-migrant protesters have also turned up twice outside the Taoiseach's home.
On Thursday 2 May as his wife was preparing their two young children for bed, a group of around a dozen masked individuals turned up outside, holding banners with anti immigrant slogans.
Images were subsequently circulated on social media.
In June another small masked anti-immigrant group waving Irish flags and demanding border closures arrived at the Taoiseach’s home and were there a short time before gardaí engaged and directed them to leave the area.
Three men, two in their 40s and another in his 30s, were subsequently arrested in Dublin.
The suspects are well known to gardaí for their presence at several anti-migrant protests all over the country, including at Ballyogan in south Dublin.
Mr Harris has previously said that he believes that people’s families and homes should be out of bounds and that it was not appropriate for protests to be held there.
