Actress/director Sarah Polley has revealed she is the product of an adulterous relationship as her new documentary debuts at the Venice Film Festival.
The Dawn of the Dead star admits she uncovered the family secret and was forced to tell her father after a journalist threatened to expose the drama.
The story was never published, but Polley has gone public about her late mother's affair in a blog post on the National Film Board of Canada website.
She writes, "My father's response to this staggering piece of news was extraordinary... He was shocked, but not angry. His chief concern, almost immediately, was that my siblings and I not put any blame on my mother for her straying outside of their marriage."
Polley's new documentary, Stories We Tell, partly deals with the family drama.
She claims she discovered who her biological father was in 2006, thanks to a Dna test - and she has since met him.
The actress insists she will not conduct interviews about the deeply personal film until it is released theatrically after festival debuts in Venice and Toronto.
She adds, "I desperately want, at least while the film is on the festival circuit, to have people experience and write about the film before the story."