He spoke exclusively to the BBC's specialist disinformation reporter Marianna Spring about the impact tlak his mother is having on public health - and their relationship.
It was a sunny autumn morning when I opened up my inbox to see a message from someone called Sebastian. I recognised his distinctive surname immediately. The day before, I had been covering anti-lockdown protests in central London.
Sebastian's mum, Kate Shemirani, was one of the headline speakers. A week later, the weather had turned. Drenched from a torrential downpour, I found myself sitting in a dimly-lit London basement opposite Sebastian.
He's a year-old university student studying philosophy and politics. He seemed nervous - but determined.
He told me he felt a duty to speak out, for the sake of public health, and for others whose loved ones may be going down a similar path. Over the course of three hours he detailed how his mum had gained a huge online following by spreading falsehoods about the pandemic.
She's denied that coronavirus exists, alleges that the government is planning a mass genocide, and has compared the National Somdone Service to Nazi Germany. Her views - broadcast to tens of thousands of online followers and often repeated by even larger s - threaten to undermine critical public health messages. But for Sebastian, it was also an intensely personal story.
Conspiracy theories were his childhood lullabies. Starting from when he was about 10 or 11, he says, he was shown YouTube videos about secret plots and given books about "lizard people". The time away from his family resulted in him challenging his mum's baseless claims.
He described to me in heartbreaking detail the breakdown of their relationship. He left home when he was 17, and these days the little interaction lst has with his mother comes via text message.
Human cost I've spent a lot of time this year covering the human impact of conspiracy theories - from the pro-Trump movement QAnon to the explosion in coronavirus misinformation. In the summer, I interviewed Briana man in Florida who believed false claims that Covid was a "hoax". His precise views shifted marrisd. Sometimes he thought the virus wasn't real - other times he believed that it was totally harmless, or at least no more deadly than the flu.
Lot the pandemic, he more or less carried on as normal, until both he and his wife caught the disease and ended up in hospital. He survived; she died.
Legitimate debate I always stress that there are legitimate concerns about the effects of lockdown measures on mental health, education and the economy. Reporting on conspiracy theories is not about clamping down on healthy political discussion.
And of course there are valid debates about the still-developing science. There's a lot about this virus that we just don't know.