The disease has spread to trees (Image: Forestry Commission)

The Department for Environment (Defra) is establishing a "disease management zone" to stop it spreading.

The disease, which has been given the name Kernovii, is distantly related to so-called Sudden Oak Death.

The aggressive disease has spread from rhododendrons to 25 trees, mostly beech, which will be destroyed over the next few weeks.

Taking action

Defra says it is the first time the disease has been identified anywhere in the world.

The disease management zone between the villages of Scorrier and Ponsanooth means access is likely to be restricted while eradication measures are being taken.

Sudden Oak Disease, which has spread to several parts of Cornwall, damages branches but Kernovii destroys entire plants and trees.

The Forestry Commission's head of plant health, Roddie Burgess, said they could not afford to let the disease take hold.

He said: "We don't really know what the total threat might be. Laboratory work we've done seems to show that beech is its favourite host, but we have found it on English Oak.

"Throughout the country we have 200m oaks, so we think we have to take this very seriously and take some action now to protect the rest of the country."