As Russia's war in Ukraine enters its 10th month, the exact number of civilians and soldiers who remain unaccounted for is unknown.
Families have become detectives using personal contacts and social media channels to try and find details about the whereabouts of their loved ones.
Evidence is mounting that Russian forces use filtration centres in occupied territories to question, detain and deport thousands of Ukrainians to Russia.
The search for those missing also involves Ukraine's police and the judiciary system, with the support of international organisations such as the International Commission on Missing Persons (ICMP).
Halyna Pastushuk reports...
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