Two more people have been arrested in relation to allegations of witness intimidation during the trial of Aaron Brady.
Mr Brady was sentenced to life in prison last month for the murder of Detective Garda Adrian Donohoe.
On Friday morning a man aged in his 20s was arrested as part of the ongoing investigation regarding allegations of witness intimidation, perverting the course of justice and the unlawful use of mobile phones in prison.
The arrested man is being detained at Portlaoise Garda station under Section 4 of the Criminal Justice Act.
On Thursday, a man in his 50s was arrested and released.
A file is to be prepared for the Director of Public Prosecutions (DPP).
It brings to seven the number of people who have been arrested in connection with the investigation.