Two men have been arrested in connection with the murder of Denis Donaldson in Co Donegal ten years ago.
The Sinn Fein official was shot dead at his home at Cloghercor in April 2006
His murder came months after it was revealed he had been working as an agent for the police and British intelligence.
The two men - who are in their 40's and 70's - were arrested in the Donegal area today.
They are being detained at Letterkenny Garda Station under Section 30 of the Offences against the State Act.