A man has been arrested in connection with the murder of Denis Donaldson in 2006.

Mr Donaldson, a former leading Sinn Féin member, was shot dead in the Doochary area of Donegal in April 2006.

It happened months after he was exposed as an agent who had worked for MI5 for over 20 years.

A man in his 40’s is being detained at Letterkenny Garda station where he can be held for up to 3 days.