Adriano Alves , the prosecutor , said in a telephone interview that taking the pilots ' passports was '' necessary to make sure two very important witnesses remain in Brazil until this investigation is carried out . ''
Adriano Alves /people/person/nationality Brazil
NNP NNP , DT NN , VBD IN DT NN NN WDT VBG DT NNS POS NNS VBD '' JJ TO VB JJ CD RB JJ NNS VBP IN NNP IN DT NN VBZ VBN RP . ''