The family of Denis Donaldson have attacked the Irish government after his inquest was adjourned for a 26th time.
They accused Dublin of “turning a blind eye to mishandling of the case”.
The murder of Mr Donaldson in Glenties in 2006, was claimed by the dissident republican Real IRA.
It happened months after the ex-Sinn Féin official admitted working for the police and MI5 for a period of 20 years from the 1980s.
After the Good Friday Agreement in 1998, Mr Donaldson, 55, occupied a key backroom role for Sinn Féin based at Parliament Buildings in Stormont.
An update of Mr Donaldson’s inquest was mentioned at the Donegal Coroner’s Court held at Letterkenny Courthouse on Friday last.
Mr Donaldson’s family say no date has been set for it to start.
Yesterday, they issued a statement through their solicitor.
It reads “The Irish State and others stand in the dock of public hypocrisy if they continue to criticise the UK government’s approach to legacy while turning a blind eye to the mishandling of the case and the injustices which our family is facing.
“As a family we shall not accept this.”
Mr Donaldson’s family claimed that An Garda Síochána, have repeatedly given the coroner timetables for progress “only to breach these without sanction”.
“Our family’s ordeal involves state agencies in both jurisdictions on this island in uncovering the facts about a criminal conspiracy which resulted in a conflict-related murder eight years after the Good Friday Agreement,” they said.
“The public interest in establishing the truth is clear.”
Last year, the Police Ombudsman in Northern Ireland found the threat Mr Donaldson was under was not properly evaluated.
However, Marie Anderson could not conclude his murder could have been prevented.
“Our family’s loss and our rights have been treated with institutional contempt,” said the Donaldson family.
“National security does not justify this.
“All we are asking is that statutory agencies, and those in authority or oversight, do their job in accordance with human rights and the rule of law.”
