A struggling fisherman found a whopping 3.4kg lump of verified ambergris that had washed up on a beach in Thailand.

Prachin Phuekphisut, 64, was walking on the white sand area of a beach babysitting his grandchildren when he noticed what he thought was ‘a big lump of fat' on the sand in Trat province on June 22.

The old man thought at first the ambergris was dried cooking fat but took the cream-coloured object home hoping that it was valuable. Excited relatives suggested he perform a lighter test to see if the waxy substance melted like caramel - which it immediately did - suggesting it was the valuable whale vomit used in the perfume industry.

Prachin showed his find to local police officers who were confident that the ambergris was genuine and helped the villager contact experts in the capital Bangkok to have a look. They later verified the find and handed him back his ocean treasure.

Fisherman Prachin said: ‘I was looking after my grandchildren so I took them for a swim on the beach. Then I found a big lump of fat. When I touched it, it felt slippery. It also had a weird smell. I was hoping it could be valuable so I took it home.'

The object that weighed 3.4kg was six inches thick and 10 inches long. It had a slightly fishy smell but not too strong and melted like fat when exposed to heat.

The old fisherman, who normally earns the equivalent of 200 GBP a month from his wooden boat - went to the Koh Chang police station to ask for help and Lieutenant Colonel Banjerd Krachangsaeng said they would assist the family.

Lieutenant Colonel Banjerd said: ‘We helped the family contact an expert in Bangkok so they could obtain a certificate of authenticity and sell the ambergris at the right price. We were confident it was real, so we just helped where we could.'

Excited Prachin said he plans to sell the ambergris and use the money to take his grandchildren on a foreign holiday, then set the money aside to send them to university.

He said: ‘I want a secure life for my children and grandchildren. I will definitely sell it once it has been verified.'

Provinces along the southeast Thai coast - where currents from the South China Sea and Java Sea merge into the Gulf of Thailand - have been the scene of dozens of finds, helped by growing awareness of what the waxy substance is.

In September last year, Thai fisherman Narong Phetcharaj found a 30kg piece of ambergris which was authenticated. He received an offer from a Chinese businessman of GBP 23,740 per kg.

In 2018, Boonyos Tala-upara, 44, found a piece weighing 10kg on the island of Koh Samui, which was valued at GBP 318,500 (USD 500,000).

Elsewhere in the world, in April 2016, a 1.57-kilogram ambergris ball found in Lancashire, England, sold for GBP 50,000 (USD 67,182) while in November of the same year, three Omani fishermen found 80KG of ambergris and sold it for GBP 2,233,000 (USD 3,000,000).

Ambergris valuations depend on the quality of the product. But based on previous valuations, Isdarit's haul could fetch up to GBP 31,850 per kg, giving him a total sale price of up to GBP 108,290.

Ambergris is produced by sperm whales when bile ducts in the gastrointestinal tract make secretions to ease the passage of large or sharp objects. The whale then vomits the mucilage which solidifies and floats on the surface of the ocean. The solid chunk has a foul smell at first but after the mucilage dries out, it develops a sweet and long-lasting fragrance, which makes it a sought-after ingredient in the perfume industry as it gives off a 'musky, sweet, or earthy scent'.