Officers tracked both the 27-year-old Syrian man and the 32-year-old female Swiss guard to a building in Romano di Lombardia in the Bergamo region in northern Italy, a spokesman for Milan police said.
The pair, having orchestrated the breakout in February, had spent a couple of weeks in the small town and appeared on the point of leaving Italy for the Middle East, he said.
A manhunt was launched after the guard helped the prisoner break out of jail in the Swiss city of Zurich, freeing him from a four-year sentence for rape.
The couple have been detained in police custody awaiting extradition.
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