The picture, reportedly taken in the Kilchoan area on the Ardnamurchan peninsula, has led some farmers to claim it is proof that Britain's largest bird of prey regularly take lambs from fields.
But conservationists say the taking of livestock is a rare occurrence and should not affect the re-introduction of the raptors.
The photograph has yet to be authenticated, but it comes at a time when there are growing demands from farmers for sea eagles to be controlled.
It also coincides with news of a successful hatching of a sea-eagle chick on an island on Loch Maree in Ross-shire.
The National Farmers' Union Scotland (NFUS) has just prepared a document on the subject, entitled Sea Eagles and Sheep Farming in Scotland - An Action Plan for Sustainable Co-Existence.
After concern among farmers in North Argyll, NFUS surveyed members along the west coast, where there are now about 80 breeding pairs of sea eagles, and in Fife and Angus. Of 103 responses, 68 reported their farming businesses had suffered from the attentions of sea eagles.
The NFUS makes a series of recommendations including that Scottish Natural Heritage (SNH), the body with overall responsibility for the sea eagles' reintroduction programme, "should make a public statement (this month) acknowledging the impact of sea eagles on sheep farming".
It also says by next month SNH web-pages and publications about the eagles "should acknowledge predation of live and healthy lambs, as well as other impacts".
By September 2016 a long-term plan for the management of sea eagles in Scotland should be in place, NFUS says.
Ross Lilley, SNH's Argyll and Outer Hebrides operations manager, said: "We acknowledge that sea eagles can be opportunistic feeders and will take some live lambs in some years in some locations, as part of a varied diet.
"However, two detailed studies have found no evidence of wholesale predation of live lambs.
"Most lambs are taken as carrion with occasional live lambs taken, which can have a significant impact on individual farmers and crofters."
This was why SNH ran a management scheme to cut "the impact of sea eagles for farmers, with financial support for practical on-the-ground measures".
RSPB Scotland's head of species and land management, Duncan Orr-Ewing, said: "Many west coast sheep farmers are concerned that the long-term success of the Scottish sea-eagle reintroduction will come at a cost to them. The current scientific evidence on sea-eagle ecology in Scotland shows only small numbers of live lambs are killed by sea eagles, although some farm businesses may be impacted more than others."
He said the RSPB was committed to find sustainable ways for the birds and farmers to co-exist.
NFU Scotland's deputy director of policy Andrew Bauer said however successful the reintroduction had been, it had come at a growing cost to those keeping sheep in some of the most economically fragile parts of Scotland.
"We believe the recommendations [the action plan] contains can secure a sustainable co-existence between sheep farmers and sea eagles," he said.
The nest at Loch Maree has been regularly used by a pair of sea eagles for the past 16 years, and last year SNH installed a remote camera. It has sent live pictures of the chick's birth via to the visitor centre in nearby Kinlochewe.