The Denis Donaldson duplicate spy murder inquest was today adjourned for the 17th time, with his family once more boycotting the hearing in protest.
A letter from Donaldson family solicitor Ciaran Shiels of Madden & Finucane said the family didn't know what further “lines of inquiry” gardai were seeking.
Mr Shiels' letter, read by coroner Dr Denis McCauley at the Letterkenny inquest, added: “Nor do we know what the status is of the Department of Public Prosecution's consideration of the file that it has in its possession now for a number of years.”
Mr Shiels said he had been instructed by the family not to attend the latest hearing of the inquest as they considered any attendance would be “a pointless exercise.”
Supt Michael Finan, applying for a continuing adjournment, said “significant leads” were being followed up.
He added that assistance was being provided by a force outside the jurisdiction and liaison was ongoing and full co-operation was being received.
Although Supt Finan didn't specify the outside force it is believed he was referring to the PSNI.
Dr McCauley said he understood the family's “frustration” but he understood the investigation was active with an intention of bringing a criminal prosecution and he agreed to a further adjournment of the inquest until April 13.
Donaldson, 56, was shot dead by gunmen in a rural cottage near Glenties on April 4, 2006.
The Real IRA claimed it was responsible.
The former senior Sinn Fein official had confessed to spying for police Special Branch in Northern Ireland and secret service MI5 just months before he was killed.