Per an article in The Guardian: At the pre-inquest hearing into the death of Russian whistle-blower Alexander Perepilichnyy, an article written by Sir Arthur Conan Doyle (published in a 1879 issue of the British Medical Journal) on the poison gelsemium was introduced as the first piece of scientific evidence. It seems that Doyle self-experimented with gelsemium, and it gave him some seriously nasty side effects. Happily, he quit doing that and just wrote about how evil the poison was.
The article, “Gelsemium: the plant that can cause convulsions, paralysis and asphyxia,” explains more about what Doyle did and how his work is being used in the hearing. Honestly, I don’t think I’ve even heard about the Perepilichnyy case prior to this — it seems like the Litvinenko death/murder got a lot more press.