Police have been given an additional three days to question nine people arrested in a major operation against dissident republicans.
The seven men and two women, aged between 26 and 50, were arrested on Tuesday.
Sources described the operation by MI5 and the PSNI as one of the most of significant in recent times.
Madden and Finucane, representing one of the men, said the PSNI went to court seeking a further five days detention.
The nine people are being questioned under the Terrorism Act.
The BBC understands this co-ordinated series of arrests was a joint operation between MI5 and the PSNI.
Security services worked with police with the intention of targeting key figures in the leadership of the New IRA.
More than two decades after the Good Friday Agreement, tackling the threat posed by dissident republican groups continues to be a substantial proportion of MI5's work.
Security sources said this was one of their most significant operations in Northern Ireland for some time.
There has been a renewed focus on the activities of the New IRA since the death of Lyra McKee, shot in 2019.
The arrests in counties Londonderry, Tyrone and Armagh are part of an ongoing investigation into the New IRA.
In the Republic of Ireland, gardaí (Irish police) carried out six searches in Dublin, Laois, Cork and Kerry as part of Operation Arbacia.
The New IRA is considered to be the largest dissident republican group and has been behind numerous attempted attacks on police officers
Journalist Lyra McKee was shot dead by a New IRA gunman while observing a riot in Londonderry on 18 April 2019.