A dog found a super-rare lump of whale vomit on a beach - which could be worth thousands.

Patrick Williamson, 37, was stunned when his pup dropped her ball and sprinted over to a mysterious rock on the shore.

Fisherman Paul knew it was ambergris - a valuable chunk of secretion produced in the intestines of sperm whales.

Whales are usually able to regurgitate problem foods but if they can't they produce a waxy substance to protect its intestinal tract.

The whale will then expel the valuable ambergris, which will float in the sea until it washes up on the shore – ready to be found by a lucky treasure hunter.

Patrick found the 5oz substance on Irvine beach in Ayrshire and is now getting it tested.

Larger lumps have sold for millions for use in the cosmetic industry.

Patrick said: "I work on a fishing boat, so I knew what ambergris was. I’ve never seen it before, but I’ve heard stories about it."

"I was walking along Irvine Beach with the dog. I clocked something on the seaweed, and the dog ran over to it and dropped her ball."

"She doesn’t usually drop her ball, so I knew there was something there."

Patrick had found a pale grey rock, with brown and amber streaks – and knowing the potential if he had struck amber, he immediately picked it up.

Ambergris is sold by weight, with one chunk found in the Canary Islands this year weighing 21 pounds – and valued at £394,000.

A common test to identify ambergris is to heat up a needle and lay it on the surface of the rock –ambergris will begin to melt into a waxy, black or brown liquid very quickly.

"I weighed it when I first got it, and it was about five and a half ounces. That’s not really that big compared to some other bits that have been found," said Patrick."

"We’ve tested it with a hot needle, and it was doing the exact same thing that ambergris would."

"People have been saying that I can take it to Glasgow University, and they’ll test it – so I’ll be doing that on my next day off."

Sperm whales are protected by law in the UK however it is legal to sell ambergris found on the shoreline.

Patrick plans to test his ambergris to ensure its legitimacy – but after that he’s unsure what to do with his find.

"Everybody’s been messaging me – one of my pals even contacted someone at the local paper," said Patrick."

"I'm not sure what I'm going to do with it!"

"I’m on the beaches all the time. I take my dog with me wherever I go, so we’ll be looking every time we land now."