Gardaí investigating the murder of former Sinn Féin official and British agent Denis Donaldson at his home in Co Donegal in April 2006 have arrested a man this evening.
The man (70) is being held at Letterkenny Garda Station under Section 30 of the Offences Against the State Act.
Mr Donaldson (56) who headed Sinn Féin's support team at Stormont, was shot dead several months after revealing he had been spying for Britain for 20 years.
Mr Donaldson moved to Co Donegal after admitting in December 2005 that he had been an agent.
He was last seen by gardaí in Glenties at 5pm on April 3rd, 2006, about 24 hours before he was murdered in his remote cottage. Gardaí found him dead inside his cottage after a member of the public noticed his door open and dialled 999.
He had suffered two shot gun wounds, one to the head and one that almost severed his hand from his arm. The IRA denied at the time it was involved in the murder, and this was accepted by Mr Donaldson's family.
In April 2009, the Real IRA claimed responsibility for the murder of Mr Donaldson at Cloghercor, Doochary, Co Donegal.