A man in his 30s has been arrested by gardaí investigating the murder of Eddie Hutch in February.
Eddie Hutch Snr, who was in his 59 and a taxi driver, was shot dead in his home at Poplar Row, Dublin 3 on February 8.
He was a brother of Gerry Hutch, aka The Monk, who attended his funeral in disguise on February 19.
A man was arrested earlier today in the Dublin area and is currently detained under Section 50 of the Criminal Justice Act, 2007 at Mountjoy garda station, where he can be held for up to seven days.
It is believed Mr Hutch, who was not involved in serious crime, was killed as a "soft target" for his family connections, in a reprisal for the shooting of suspected gangland figure David Byrne days earlier.
Byrne's murder during a packed boxing bout weigh-in at the city's Regency Hotel was a suspected retaliation for the shooting dead of Mr Hutch's nephew Gary Hutch in the Costa del Sol last September.
Gardaí are continuing to appeal for anyone with information to contact the incident room at Mountjoy garda station on 01 6668600, the Garda Confidential Line 1800 666 111 or any garda station.