The Peru international joined the Royals from Pacos de Ferreira last summer but only made five Championship appearances before signing for Vitoria on loan in January.
Hurtado scored once in seven appearances as Vitoria finished 10th in the Premeira Liga.
The 26-year-old has made 25 appearances for Peru, scoring two goals.
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Reading midfielder Paolo Hurtado has rejoined Portuguese side Vitoria de Guimaraes on a season-long loan.