A mother from Ukraine signs a contract, hoping that it will help her young daughter. Viktoriia has a brain tumour: her story is plastered all over social media despite her family’s request that the video they made isn’t shared.

Olena says she wasn’t given time to read the contract properly. When we look more closely, it makes for shocking reading. Now she knows the truth, she wants to stop the scammers, agreeing to help us go undercover.

Season 10 of World of Secrets, The Child Cancer Scam, is a BBC Eye investigation for the BBC World Service.

Please note, the image is being used for illustrative purposes only and the child depicted is a model.