It was sanctioned and planned by the German secret service (Abwehr) and executed successfully in May 1940.
ɪt wʌz sˈæŋkʃənd ænd plˈænd baɪ ðə dʒˈɜːmən sˈiːkɹᵻt sˈɜːvɪs ɐbwˈeɪɚ ænd ˈɛksᵻkjˌuːɾᵻd səksˈɛsfəli ɪn mˈeɪ nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi.