Three men, who were arrested on Monday, have all been released without charge.
Gardai have arrested a man as part of the investigation into the murder of a 17 year old boy in January 2020.
The man in his 20s is being held at a Garda Station in Dublin.
Three men, who were arrested on Monday, have all been released without charge.
Files will now be prepared for the Director of Public Prosecutions.

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