Some scientists say the fungus now ravaging trees across Europe is the same as a native species from Japan.

However, the Asian version of the fungus seems to cause no harm to the local Manchurian ash trees there.

Researchers speaking to the Radio 4 programme The Tree Scientists described the misidentification of the fungus.

Joan Webber, principal pathologist at the Forestry Commission, told the programme: “Scientists working together in Japan and Germany have been looking at a fungus associated with native ash trees in Japan. And what they’ve found is that this fungus appears to be the same one causing ash dieback in Europe and now in Britain.”

“Currently when it infects a nursery for instance, it kills all of the saplings, by killing its host it ultimately leads to its own demise and itself dies out. A successful fungus co-exists with its host tree, so they will both survive.”