Putting a limit on the amount of land in Scotland that one person can own has been suggested by former Scottish Labour minister Peter Peacock.
Mr Peacock has put forward the idea in a discussion paper, one of a number commissioned by the Scottish Land Commission on land reform.
In Land: For the many, not the few?, he argues that half of all privately-owned land is held by fewer than 500 people.
He said huge estates created local land monopolies.
Scottish Land and Estates, an organisation representing the interests of landowners, said a "meaningful debate" should be held about land use, rather than ownership.
It added that the land commission's research also came only two years after the Land Reform Act was passed by the Scottish Parliament, and "which was the conclusion to a long debate".
Mr Peacock, who is also a former leader of Highland Council, has suggested imposing an absolute limit on the size of landholdings as one potential solution.
Tax changes - such as the introduction of a land value tax - could also bring about more equitable distribution, he said.
Mr Peacock also pointed out that crofters were subject to a residential requirement and suggested that this could be applied to absentee landowners.
David Johnstone, chairman of Scottish Land and Estates, said the organisation acknowledged that land reform was an ongoing process.
He said landowners supported independent research that could inform how ownership could influence the best possible use of land.
Mr Johnstone added: "However, we are disappointed when similar research, already published by the Scottish government as recently as July 2016, appears to have been forgotten.
"Amongst other findings, that research stated that it was 'too simplistic to conclude that scale of land ownership is a significant factor in the sustainable development of communities'."