The inquiries were meant to finish last week, but only one has heard any witnesses, while one family is without legal representation and another said they felt their inquiry was “at a standstill”.
The minister for justice is now seeking progress reports from the five retired judges heading the inquiries.
Four inquiries concern allegations of Garda failings or misconduct in the investigations into the deaths of four men: Patrick Nugent, who died after receiving injuries at Bunratty Folk Park in 1984; James Clancy, killed by a lorry in Tullamore in 1988; Shane Tuohey, who disappeared in Clara in 2002 and whose body was found in a local river a week later; and John Kelly, drowned at Britain Quay, Dublin, in 2008.
The fifth inquiry centres on unsubstantiated claims of fraud against former Isme CEO Frank Mulcahy in 1998.
Edwin Tuohey, brother of Shane, said there were growing frustrations about the way they were proceeding. His family sought to change solicitors and, while waiting for a new legal team to be approved, they heard at least one Garda witness may have been called in their absence.
“We’ve asked for clarity on a lot of things because we don’t know what’s happening,” said Mr Tuohey. “We see Maurice McCabe up in Dublin Castle — and that’s only right — but we’re in a half-derelict building away from the public eye and we’re forgotten.”
Emma Kelly, sister of John Kelly, said the family met their judge last month but said: “We’re still quite in the dark with a lot of stuff. There’s nothing set in stone about the people they’re going to call and how they’re going to proceed. We’re sort of at a standstill.”
The James Clancy inquiry had three hearing days last month.
“We’re going the best of all them,” said his son, Joe Clancy. “But we’d want to be because this won’t be the end for us. The terms of reference only look at what happened to the files in my father’s case but I have a right to know who killed my father so we need this to move along.”
The Nugent family met their judge last week. They, too, have concerns about the terms of reference.
Mr Mulcahy’s inquiry is understood to be preparing to call witnesses.
Darragh Mackin of the Kevin Winters law firm, which represents all but the Tuoheys, said the complexity of the cases may not have been appreciated when the inquiries were set up.
The Department of Justice said: “Interim reports have been received in the case of all five inquiries which indicate the progress that is being made. However, the minister has requested a further updated report in relation to each of the inquiries with a view to determining a revised timeframe for submission of a final report in each case.”