Migrant rights advocate held in Tunisia under anti-terrorist investigation / EU refuses to publish findings of Tunisia human rights inquiry / EU watchdog issues criticism of EU-Tunisia deal over human rights concerns / Tunisia's anti-migrant measures spark human rights concerns / World News in Brief: 'Historic drought' in southern Africa, human rights in Tunisia, accountability essential for Pakistan mineworker killings / EU fears for its human rights credibility as Tunisia crushes dissent, leak shows / Migrants face misery in Tunisia. Rights activists fear that the EU deal will make things even wors