Animal dewormer and a drug used to treat scabies are being sold and promoted as unproven cancer treatments, a BBC investigation has found. Following a tip off, an undercover journalist was able to buy fenbendazole and ivermectin from a stairlift salesman in south Wales, and also found them for sale on Amazon. Amazon said it had "proactive measures in place" to stop prohibited products being listed by third-party sellers. Senior doctors are worried vulnerable patients could be put at risk by taking the medicines, as they say it could harm or delay conventional treatment. Six months ago, Rebecca Holder contacted the BBC after a visit from stairlift salesman Jason Sarver.