Two people, aged 30 and 33, were arrested by earlier today as part of the ongoing TIU investigation.
They were detained in Carricfergus under section 41 of the Terrorism Act.
The suspects have been taken to the serious crime suite at Musgrave PSNI station for questioning about the murder.
Gilmore was shot in Carrickfergus on Monday, March 13 around 2.30 pm as he drove his white Vauxhall Insignia car along Pinewood Avenue in the town.
In a statement, the PSNI said TIU detectives “continue to appeal to anyone who was in the area at the time of the shooting and who witnessed the attack to contact them in the incident room on 02890 259542, phone police on 101 quoting serial 605 13/03/17”.
Alternatively they can phone Crimestoppers anonymously on 0800 555 111.