Ken Wilman told British broadcasters that he had been walking along Morecambe beach in northern England when his dog, Madge, discovered a hard, soccer ball-sized piece of smelly rock.
"She wouldn't leave it alone. I picked it up and it smelt horrible so I knocked it with my walking stick and a small lump came off," he told Sky News television in comments broadcast Thursday. "I put both pieces back on the beach but something in the back of my mind told me it might be something unusual."
One Google search later and Wilman realized that Madge had found ambergris, a waxy byproduct of sperm whale digestion that has traditionally been used in perfumes, spices, and medicines - and can fetch large sums of money. He said he immediately drove back to the beach to find the ambergris. He said he has been offered €50,000 ($68,000) for the musky material.
Callum Roberts, a professor of marine conservation at the University of York, said the find appeared legitimate.
"It's a waxy, yellow-gray piece of flotsam. I'm sure that 95 percent of people would walk past it without further thought," he said in a telephone interview. He praised Wilman's quick thinking, invoking the scientific dictum that "fortune favors the prepared mind."
Wilman, 50, had a slightly different take on his find, telling BBC television that people should trust their dogs.
"If your dog pays an interest in something, YOU pay an interest in something," he said. "Because you never know. There's gold out there on that beach - floating gold."