Jon Stewart on new film 'Rosewater'

When the London-based journalist Maziar Bahari was imprisoned in Iran while covering the elections in 2009, his months of interrogation there inspired him to write a book and it has now been turned into a new film called 'Rosewater'.

Directed by Jon Stewart, the legendary anchor of US television's "The Daily Show" and Maziar Bahar both talk to the BBC's Andrew Marr.

Rosewater is headlining the London Film Festival tonight.

UK viewers can watch the Andrew Marr Show in full for seven days