A 52-year-old man from Sydney, Australia, was arrested Monday afternoon in Louisville for his alleged role in a hoax in which a fake collar bomb was tied to the neck of an 18-year-old woman, Sydney's Daily Telegraph's Mark Morri reports. The FBI and Australian are jointly investigating the case, and the man in Louisville hasn't been charged. Australia is expected to apply for his extradition. On August 3, Madeleine Pulver spent 10 hours with what appeared to be a bomb strapped around her neck after a man wearing a ski mask broke into her family's home in Sydney. The man wanted to extort money from Pulver's family; her father is a wealthy businessman.