A woman cannot believe her luck after she found what is believed to be a piece of expensive ambergris washed up near her beach house.

Siriporn Niamrin, 49, revealed she was walking along the sand after a rainstorm when she noticed the bizarre mass in Nakhon Si Thammarat province, Thailand, on February 23.

Ms Niamrin investigated the substance and found it had a fishy smell.

She dragged it back to her house about 500 metres away in hopes that it could be something she could sell.

The woman asked her neighbours for help and was shocked when they informed her that it could be ambergris, also known as whale vomit.

Ambergris is a result of sperm whales bile ducts in the gastrointestinal tract making secretions to ease the passage of large or sharp objects.

The whale vomits the mucilage, which solidifies and floats on the surface of the ocean.

The solid chunk has a terrible smell at first but after the mucilage dries out, it develops a sweet and fragrance that lasts a long time – making it a deeply sought-after ingredient in the perfume industry.

They are now waiting for experts to visit her house to confirm that the lump is genuine ambergris.

The oval-shaped lump weighed in at 7kg and was around 30cms wide and 60cms long.

The weight gives the chunk of ambergris an estimated value of around A$357,000, based on previous sales.

“If I really have the genuine ambergris, I can help my community once I find a buyer for it,” Siriporn said.

“I feel lucky to have found such a large piece. I hope it will bring me money.

“I’m keeping it safe in my house and I have asked the local council to visit to check it.”

This article originally appeared on Over60.