The duo were picked up in Dublin yesterday and last night were being questioned at Clontarf and Raheny Garda Stations.
Both are suspected of peripheral involvement in Kelly's death. They were previously arrested less than a week after Kelly was killed after the chief suspect was charged in the case.
The Dubliners were released without charge after being questioned for a number of days at a north Dublin garda station 14 months ago. Since their release, the suspects have continued to be under surveillance by gardai and sources say they have continued to be involved in criminal activity.
One of the suspects, aged 43, who is from the north inner city, is on bail in relation to IRA charges. The second suspect is a 35-year-old IRA man from Tallaght who previously served a four-year jail sentence for IRA membership.
A total of eight people have been arrested as part of the detailed investigation into the fatal shooting including the two re-arrested men but just one person has been charged in connection with it.
The arrests happened after it emerged at an inquest on Tuesday that Kelly's son Eamon Jnr died from drug-related injuries three weeks after his father was killed. He had taken a cocktail of drugs at a friend's house in north inner city Dublin.
Sean Connolly (35), of Bernard Curtis House, Bluebell, Dublin 12, has been charged at the Special Criminal Court with murdering Eamon Kelly on December 4, 2012.