A second man arrested as part of a Garda investigation into the murder of former Sinn Féin member and British agent Denis Donaldson has been released without charge.
A Garda spokesman said on Wednesday the man in his 30s, who was arrested on Sunday, was released without charge on Monday night. A file will be prepared for the Director of Public Prosecutions.
A dissident republican arrested in Co Donegal in connection with the murder of Mr Donaldson was also released without charge on Monday.
Mr Donaldson, who the Real IRA said it murdered at a lonely farmhouse near Glenties in Co Donegal in 2006, was a senior figure in both Sinn Féin and the IRA, and a trusted ally of Gerry Adams and Martin McGuinness.
The dissident republican, who is from Derry, was arrested by gardaí at a commemoration ceremony in west Donegal on Sunday and taken to Letterkenny Garda station for questioning. This was the second time he was questioned by gardaí about the murder.
Mr Donaldson served periods in Long Kesh, and was a close friend of hunger striker Bobby Sands. After the 1998 Belfast Agreement and the creation of the Northern Executive and Assembly, he was Sinn Féin's senior administrator at Stormont.
In October 2002, Mr Donaldson and two other members of Sinn Féin's Northern Assembly staff were arrested in connection with an alleged republican spy ring operating at Stormont. Dubbed "Stormontgate", it caused unionist outrage and led to the collapse of the Northern Executive and the return of direct rule from Westminster.
Charges against Mr Donaldson were dropped in December 2005 in the “public interest”. It prompted speculation that the “public interest” was a pretext to protect an agent or agents.
A week later Sinn Féin said Mr Donaldson was a British agent, and expelled him from the party.
In a statement Mr Donaldson said he was recruited “in the 1980s after compromising myself during a vulnerable time in my life”.
“Since then I have worked for British intelligence and the RUC/PSNI Special Branch. Over that period I was paid money.”
He insisted he was not involved in any republican spy ring in Stormont.
Born in 1950, he is believed to have joined the IRA in the 1960s before the Troubles began. He was a key player in the republican movement.
He was also involved in setting up Friends of Sinn Féin in New York, and in the late 1980s took part in efforts to secure the release of Lebanon hostage Brian Keenan.
He stood for Sinn Féin in East Belfast in the 1983 Westminster general election, winning 682 votes.
The inquest into Mr Donaldson’s death has been delayed at least 19 times.