Three people who were arrested in connection with the murder of Lee Slattery have been released without charge.
Two men and a woman, in their 30s, were arrested as part of the investigation.
Files will now be prepared for the Office of the Director of Public Prosecutions following their release.
One man has been charged with Mr Slattery's murder.
Kurt Ryan, of Cliona Park, Moyross, Limerick, appeared before Limerick District Court
Mr Ryan was remanded in custody to Limerick Prison to appear again before the district court next Tuesday via video link.
Mr Slattery's body was discovered in a shallow grave on the outskirts of Limerick city 15 years ago.
Gardaí say investigations are ongoing.
