Police are hunting a thief who stole a rare and highly sought mushroom which is said to alleviate the symptoms of dementia.

Three of the legally protected ‘bearded tooth fungi’ specimens were sliced off trees in the New Forest, in the latest theft of the mushroom in the area.

The fungi’s scientific name is Hericium erinaceus, but it is also commonly referred to as ‘Lion’s mane fungi’ because of its flamboyant long spines that look like a shaggy mane.

Scientists in Japan tested the effectiveness of the fungi on a group of men aged 50-80 to see if it had an impact on their cognitive function.

After taking a course of tablets made of the powdered mushroom, their cognitive impairment improved, with laboratory tests showing no adverse effects.

The crime of picking one of these rare species without authorisation can result in six months imprisonment and an unlimited fine.