Andrew Moran, 31, from Salford, was charged with a 2005 armed robbery against Royal Mail guards in Lancashire.
During the trial, in February 2009, assaulted four security guards, jumped over the dock and escaped.
He was convicted in his absence of conspiracy to commit armed robbery, and placed on the Serious Organised Crime Agency's most wanted list.
The guards had been threatened with a gun, machete and baseball bat. One of them was assaulted before the robbers made off with £25,000.
He was found yesterday by the swimming pool of a luxury villa on Spain's Costa Blanca, and has been detained in the Alicante resort of Calpe.
Spain's National Police said Moran confronted officers when they tried to arrest him, and that they recovered two handguns, 60 rounds of ammunition and a machete.
Det Ch Insp Janet Hudson, of the north-west regional organised crime unit, said: "Extradition proceedings are now under way.
"It just goes to show that we will stop at nothing to capture criminals wherever they are in the world."
Matt Burton, the agency's head of investigations, said Moran had changed his appearance and used false identities, but there was "no hiding place".
Moran will appear at a court in Madrid tomorrow.
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