US film star Ben Affleck unveiled his new film as a director at the San Sebastian Film Festival Saturday: a real-life tale of spies posing as filmmakers in revolutionary Iran.
"You would never believe the story if it weren't based on real events," he told reporters at the festival, one of Europe's top international film gatherings.
A satirical thriller, his movie "Argo" recounts events of 1979, when US diplomats took refuge in the Canadian embassy in Tehran after revolutionaries took others hostage in the American one.
A CIA hostage rescuer, played by Affleck, plans for agents to pose as filmmakers shooting on location in Iran in order to rescue the diplomats -- aided by colourful Hollywood producers played by John Goodman and Alan Arkin.
"There are issues that were really close to what happened and I stuck as meticulously as possible to the events," Affleck added.
On Sunday the San Sebastian festival is to hand its lifetime achievement awards to US film star John Travolta and director Oliver Stone.
Travolta appears in Stone's latest film, the crime thriller "Savages".