Ivermectin is an anti-parasitic drug used to treat conditions like scabies, while fenbendazole is an animal dewormer.
The BBC has seen videos and social posts with thousands – sometimes millions – of views, with unproven claims that these medicines could help treat cancer.
Hollywood actor Mel Gibson claimed on a popular US podcast that the drugs successfully treated three of his friends who had cancer.
“Jason started to say that he could get hold of a treatment that wasn’t available on the NHS, that was known to shrink brain tumours,” Rebecca said.
“So I wrote down everything he said about these medicines…fenbendazole, ivermectin…I couldn’t quite believe what he was saying.”
Rebecca said Sarver offered to sell her dad, from Monmouthshire, the medicines.
An undercover BBC reporter contacted Sarver posing as someone with a relative who had cancer.
He repeated the same claims, and sent a link to videos making unproven assertions that the drugs were effective against cancer.
“I do a lot of research, medical papers, white papers, anything that comes out fresh, I am on it,” Sarver said.
“I’m not a doctor, I just passed what I hear on.”
He went on to supply the BBC with fenbendazole and ivermectin tablets for £100 which he said would be “two to three months’ supply” to treat lung cancer and “other cancers as well”.
He said his work selling stair lifts meant he saw “a lot of ill people”.
“I can’t help myself, I’ve got to tell them about it,” he said.
