Inspectors were visiting countryside in Blackwood, near Caerphilly, South Wales, when they came across a field of stumps.
The hedgerow beeches are thought to be around 150-200 years old.
Natural Resources Wales have launched an investigation into the felling and have said anyone wanting to chop down so many veteran trees would need a licence.
Jim Hepburn, regulatory woodland officer at Natural Resources Wales, said: ‘This is a devastating case which will have a terrible impact on the local environment and no doubt be very upsetting for local people.
‘These trees would have been around 150 – 200 years old and would have provided valuable habitat for wildlife.
‘We continue to investigate how this felling has happening, and will take the necessary action against those responsible.’
TO BE CONTINUED ON
Mystery tree feller chops down 200 ancient beeches leaving environment bosses completely stumped