Sources tell Reuters that June release of businessman with US permanent residency, after 4 years in prison, was meant as an opening for talks between Washington and Tehran

General says 'videos and confessions' will be published at a later date, boasts Tehran and its allies have formed an 'international anti-spying network' against US

Nizar Zakka was arrested in 2015 after attending conference in Tehran; Hezbollah chief plays role in his release

Nizar Zakka, an internet freedom advocate, was incarcerated after visiting Tehran in 2015; sources say development is a 'sign of respect' to Hezbollah

Nizar Zakka was arrested in 2015 for alleged 'deep ties' to US military and intelligence