A 34-kilogram pearl from a giant clam left hidden under a bed for 10 years could prove to be the biggest in the world.

The enormous pearl had been kept as a lucky charm before being passed to a family member who works at a tourism office on the island of Palawan in the Philippines.

The tourism officer, Aileen Amurao, has now launched a worldwide appeal for "help from gemologists" to see if the office's new star attraction can be authenticated.

The pearl has gone on display in the atrium of New Green City Hall in Palawan's Puerto Princesa City, which is renowned for its giant organic gems.

"The Puerto Princesa City would likely earn another prestigious title and a record breaker for having the WORLD'S BIGGEST NATURAL GIANT PEARL FROM A GIANT CLAM (34 Kilograms) after being certified for its authenticity," Ms Amurao wrote on Facebook.

She added: "All recorded giant pearls in the world came from Palawan Waters."

The current largest known pearl in the world was found in Palawan sea in the 1930s.

The Pearl of Lao Tzu, previously known as the Pearl of Allah, weighed 6.4 kilograms.