Over a long career, Dr Kruszelnicki, often referred to as Dr Karl, has built a reputation for trust and honesty, promoting knowledge of science and debunking misleading public claims.
He now unwillingly finds himself a face of online scams.
“There’s hundreds of people advertising this stuff with my name and face on different sites around the world,” he said.
Since late March, hundreds of ads featuring fake endorsements from Dr Karl for various health products have been published on Facebook and Instagram.
When users reported them to Meta, the owner of the platforms, they were told the ads did not breach its advertising standards.
After being contacted by the ABC, Meta removed the content, but days later new versions of these fake endorsements are circulating on its platforms.
Celebrity endorsement scams have been around for years, but recent improvements in generative AI have provided scammers with a new toolbox of tricks, from fake videos and cloned voices, to whole fake news websites. The automated content-creation tools can quickly spin a web of deceit, designed to snare victims without them realising.
When the ABC investigated the companies behind the fake Dr Karl ads, it found a murky world of AI content, affiliated advertising, and elusive company directors with a string of companies to their names.
As fake endorsements blur the line between fact and fiction, the big tech companies that accept advertising money from the scammers are under increasing pressure to take action.
When Fred, who has asked to remain anonymous, saw what appeared to be Dr Karl promoting a blood pressure pill in an ad on Instagram, he had no reason to think the video or the endorsement itself was fake.
“I thought he’s dinky-di so there’s no problem,” the retired landscape gardener from Victoria said.
“It was the endorsement that convinced me to give it a go.”
The video, generated with the help of artificial intelligence (AI), featured what appeared to be Karl Kruszelnicki speaking about a “natural remedy” that cleared his “vessels” and made him feel decades younger.
