A giant jawbone in a Cornish stately home has at last been found to be from a fin whale – thanks to a mixture of cutting edge DNA analysis and archival research.

The jawbones stand either side of a hall door at the National Trust’s Cotehele House. Each measures nine feet in length.

They were originally believed to belong to a minke whale. But DNA analysis by the Waterford Institute of Technology has revealed that the bones are from a fin whale, leading house staff to christen the whale ‘Finella.’

Nick Stokes, acting house and collections manager at Cotehele, said: ’Cotehele was always intended show off the Edgcumbe family’s collection of tapestries, old oak furniture, arms and armour and other paraphernalia.

’We knew so little about the whale bones here. It was only after our head of nature conservation told us the bones were too big to belong to a minke whale that we started digging.’

Conservators at Cotehele sent a sample from the jawbones to Dr Catherine O’Reilly at the Waterford Institute of Technology.

Dr O’Reilly, who has been analysing DNA samples for over 30 years, said: ’There was a perfect match for the fin whale.’

But conservators still didn’t know where the bones were from.

There was some speculation that the whale bones could have belonged to a blue whale which washed up at Mevagissey in 1647.

The truth was only discovered in December after a hunt through old documents at Cotehele.

It uncovered a copy of a partial inventory of the house’s collection, apparently written by owner William, 4th Earl of Edgcumbe in 1887.

The inventory said the jawbones came from a 61ft whale that landed on Colona Beach, near Bodrugan, on January 2, 1875.

Nick said: ’Finding the inventory came as a total surprise to our team at Cotehele. It’s great to have finally solved the mystery of Cotehele’s whale bones.’

Visitors will be able to see the newly identified fin whale bones when Cotehele House reopens on March 11.