A British man has been offered more than $50,000 for a rare piece of whale vomit that his dog found on Morecambe beach in northwest England.

Ken Wilman was walking his dog Madge along the beach, when the dog noticed a smelly rock with a waxy texture and yellowish color, reports The Australian.

At first, Wilman left the rock on the beach and returned home. "When I picked it up and smelled it, I put it back down again and I thought 'urgh'," Wilman told BBC.

After doing some research on the Internet, Wilman figured out that the rock could be ambergris, a valuable substance that is found in the digestive system of the sperm whales. He then went to the beach and retrieved the seven-pound rock.

Ambergis is a natural excrement ejected into the ocean from the sperm whales' abdomen. When the substance floats on water, it gets hardened and eventually gets collected along the shores.

The substance initially gives a foul smell, but as it gets exposed to the sun and salt water over the years it becomes waxy, according to the BBC. Ambergis is valuable, as it is used in perfume-making and its fragrance varies, ranging from earthy to musky to sweet-smelling.

Wilman is waiting for tests to confirm that the rock is ambergris (also known as floating gold), but he said that he has already been offered more than $50,000 for the valuable object.

This is not the first time that ambergris has been spotted on a beach. Last year, an 8-year-old boy found a one-pound piece of ambergris while he was walking along the beach with his dad in Dorset. The substance was said to be worth up to $63,000.