The film, Smoczyńska’s English-language debut, is a Polish-US-British co-production.
The Silent Twins is based on the book of the same title by investigative journalist Marjorie Wallace. It tells the story of twins who, after spending 14 years at Britain's high-security Broadmoor psychiatric institution, speak to each other only in a language of their own creation.
The Deauville Film Festival, which began on Friday, runs until September 11.
Earlier this year, The Silent Twins was shown in the 'Un Certain Regard" section of the Cannes Festival.
Later this month, it will be screened at the Polish Film Festival in Gdynia, before going on general release in Poland at the end of October.
Smoczyńska’s credits include The Lure (2015) and Fugue (2018).
(mk/pm)