Campaigners have hit out at plans to trap escaped beavers that are now living wild on rivers in Tayside.
Scottish Natural Heritage (SNH) announced earlier this week that it intended to recapture up to 20 beavers that have escaped from private collections.
Naturalist Derek Gow said the plan was "ill considered and profoundly wrong".
But SNH said it was necessary for the animal's welfare and because their release had been illegal.
A formal trial reintroduction of beavers is currently under way in Knapdale, Argyll.
The escaped beavers are currently living on the River Tay and its tributaries in Perthshire and Angus.
Mr Gow said: "If Scottish Natural Heritage decides to move against this population then they will do so for reasons which have nothing to do with welfare and little with legality.
"Their action will be principally inspired because they are the 'wrong beavers' in their reckoning.
The naturalist, who quarantined the animals released in the Argyll trial, said the trapping plan was being done to "quietly assuage" landowners and to protect a "perceived threat" to the Knapdale project.
Some of the feral beavers in Tayside have bred since their escape
Campaigners, who have set up a Facebook group calling to "save the free beavers of the Tay", are concerned a trapping trial that captured adults only would leave young kits to fend for themselves.
Mr Gow added that he believed the beavers will be killed rather than rehoused as there was no zoological facility in Britain or Europe with the capacity to keep them.
SNH told BBC Scotland the organisation had been advised that the two 18-month-old kits were be capable of survival without their mother.
A spokesman said: "Had the keepers of these animals fulfilled their responsibility and prevented their escape in the first place, we would not be in this position.
"That is why we are now liaising with the keepers of beavers to ensure that their collections are appropriately kept with regards to both security and their welfare.
"The fact remains that leaving these animals in the wild would mean choosing to ignore well-established wildlife legislation. This is not something that SNH, or any other government organisation, can do."
SNH said the animals needed to be recaptured because the Scottish government may decide to abandon the reintroduction of beavers after the Knapdale trial.
The spokesman added that the Royal Zoological Society of Scotland would house the captured animals until permanent homes could be found for them.