Police in Belfast last night arrested a 40-year-old man in connection with the activities of Basque separatists.
The man was arrested in Belfast city centre in a joint operation between the PSNI serious crime branch and Spanish police.
He was brought to the Antrim Serious Crime suite for questioning.
In March, a Belfast judge ordered the extradition to Spain of a former Eta leader to face a charge of justifying terrorism.
Jose Ignacio De Juana Chaos (54), lodged an appeal and was out on bail before a hearing due in June. However a court hearing at the end of April was told he had disappeared after not having reported to police as required under the terms of his bail for more than a month.
His appeal is due to be heard in his absence on Monday.
Eta is held responsible for the deaths of more than 800 people in its 40-year campaign to carve out an independent Basque state in northern Spain and southwestern France.
Additional reporting: PA