The concerns were raised in response to a national consultation being conducted by the Lynx UK Trust, which aims to bring back the large cat to areas in Aberdeenshire, Argyll and the Borders.
The body has been seeking views ahead of applying for a licence to conduct a trial reintroduction in 2016.
As part of the consultation, a report published by the trust suggests bringing back lynx could generate millions of pounds for the rural economy through eco-tourism and environmental benefits from controlling deer populations.
The paper lists the prey of the lynx as mainly “small ungulates” such as roe deer, but notes that each adult cat will consume “0.4 sheep per year”.
Members of the landowners’ association Scottish Land & Estates SLE) have accused the trust of exaggerating the benefits of reintroducing the large predator to the wild.
They claim the impact on farmers and rural communities is not yet fully understood and needs further analysis before further steps are taken.
“Overall, we feel many of the potential benefits of lynx reintroduction are overstated,” said Anne Gray, environmental policy officer for SLE.
“We do not believe the public support as quantified by Lynx UK Trust is accurate, and we are not convinced of the benefits to lynx conservation itself of some of the proposed reintroduction sites.”
She said the proposal “downplays some of the possible negatives” for rural businesses such as farming and forestry.
But Lynx UK Trust director Emily O’Donoghue hit back at the criticism. She insists the economic benefits of reintroduction were “rigorously generated” by environmental economists”.
She said: “Lynx have the potential to be the saviour of many failing rural economie.”
A recent survey by the trust showed 91 per cent of people support the plan.
“You can’t get more unanimous than that,” she added.