Police are looking for the culprit of a number of tree-fellings along the bank of the River Thames in Surrey.
The sudden loss of trees - dubbed the chainsaw massacre - was first reported on 28 March.
Since then, more than 20 completely healthy trees have been cut down along the two-mile stretch between Walton-on-Thames and Weybridge, Surrey Police and Elmbridge Council said in a statement.
On 7 April, a Facebook group called Elmbridge Tree Patrol was set up so local community members could share information about the phantom lumberjack and assist with finding the culprit.
The creator of the group wrote: “As you all know there's a maniac going around Weybridge, Walton-on-Thames and Cobham chopping down trees ruining the environment, ecosystem, habitats and making everyone upset.”
Numerous photographs posted in the group show chopped down trees strewn over grass, near roads and in the river next to tree stumps, causing potential danger to traffic and canoeists.
Police have asked the 505 members of the Facebook group not to go out looking for the culprit, according to a post.
Some of the trees that have been cut down were memorial trees dedicated to loved ones, Walton South councillor Christine Elmer said in a tweet.
Elmbridge Borough Commander Inspector Bert Dean said: “I do not underestimate the impact this mindless damage has on the local community as well as the risk it has posed to motorists by obstructing roads.
“We are looking at every opportunity to identify who is responsible for this and will continue to work closely with Elmbridge Borough Council to tackle this issue. If you have any information which could help, and you have not already got in touch, please contact us. ”