The man detained at Listowel Garda station in connection with the murders of Michael Hanrahan and his son Denis has had his period of detention extended for a further period of 24 hours.
The 30-year-old man was arrested in Tralee last night at around 7.30pm.
Gardaí say he is from north Kerry but not from the Moyvane area.
The bodies of 60-year-old Michael and his 27-year-old son Denis were discovered in their home at The Hill, Moyvane, on Thursday morning.
Meanwhile, a second gun is being forensically examined in connection with the murders.
Gardaí will not say where the gun was located or how significant it may be to the murder investigation.
A legally-held shotgun taken from the Hanrahan home on Friday afternoon is already being balistically examined at garda headquarters in Dublin.
Eight used shotgun cartridges found in the house are also being tested and examined for traces of DNA, at the forensic science laboratory.
A widespread search of the area around the Hanrahan home is continuing.
A number of other people have been questioned about their deaths but none of these were being considered suspects.
A team of over 70 gardaí are involved in the investigation, one of the most extensive the county has seen in recent years.
The parish priest of Moyvane, Fr John Lucid, has said the community felt a deep sense of pain and loss at the horrific deaths of the father and son.
