Gallagher died from a number of gunshot wounds.
Gardaí are renewing their appeal for information surrounding the murder of Paul Gallagher in 2014.
At approximately 10.30pm on Monday 28 July 2014, Gallagher travelled to Ballymacan, in Collon, Meath, along with a man.
In Tullyallen village, prior to arriving at their destination, Gallagher was joined by two more men.
Two days later, the 26-year-old's body was discovered in a field and reported to An Garda Síochána.
The investigation found that Gallagher had died as a result of a number of gunshot wounds.
Gardaí made an appeal for information at the time, including an episode of Crimecall in September 2014. A number of arrests were made in relation to the investigation, but no person has been charged with the murder.
"Investigating Gardaí continue to appeal for information in this case and believe that a number of people have yet to come forward who may now be in a position to assist in bringing those responsible to justice," Gardaí at Navan Garda Station said.
"With the passage of time some person may now be in a position to provide information to investigating Gardaí that they could not provide at the time, or maybe some person who did provide information at the time may be now in a position to provide further information."
Anyone with information can contact Navan Garda Station 046 9036100, the Garda Confidential Line 1800 666 111 or any Garda Station.
