Former regional Catalan President Carles Puigdemont carries yellow bags with books of Catalan authors, as he arrives at the prison in Neumuenster, Germany, March 25, 2019. Carles Puigdemont donates 100 books of Catalan authors in German translation for the prison library, where he was imprisoned a year ago. (Carsten Rehder/dpa via AP)

BERLIN (AP) — The former president of Spain's Catalonia region, Carles Puigdemont, has returned to a German prison where he spent nearly two weeks last year to drop off a donation of books.

Puigdemont's visit to the prison in Neumuenster on Monday came a year after he was arrested in Germany's far north as he tried to drive from Finland to his base in Belgium. An attempt to extradite him to Spain, which he fled in 2017 after his regional government held an unauthorized referendum on independence from Spain, later collapsed.

German news agency dpa reported that Puigdemont brought a donation of 100 books by Catalan authors translated into German, saying he wanted to express gratitude for his treatment in prison.

Puigdemont is seeking a seat in the European Parliament in May elections.

Former regional Catalan President Carles Puigdemont carries yellow bags with books of Catalan authors, as he arrives at the prison in Neumuenster, Germany, March 25, 2019. Carles Puigdemont donates 100 books of Catalan authors in German translation for the prison library, where he was imprisoned a year ago. (Carsten Rehder/dpa via AP)
Former regional Catalan President Carles Puigdemont arrives at the prison in Neumuenster, Germany, March 25, 2019. Carles Puigdemont donates 100 books of Catalan authors in German translation for the prison library, where he was imprisoned a year ago. (Carsten Rehder/dpa via AP)