Highland Titles was accused of going against "Scotland’s great tradition of the right to roam".
It owns 130 acres of Glen Nant in Argyll and Bute, with its website saying: "Known as Scotland’s rainforest, the ancient oak woodland at Glen Nant is a special place, as evidenced by the SSSI [Site of Special Scientific Interest] and SAC [Special Area of Conservation] status.”
However, it added: "We will not sell plots of land from this location and we do not encourage you to visit as we wish to keep the land untouched and wildlife undisturbed."
After being approached by Scotland on Sunday, it updated its website to read: “We will not sell plots of land from this location and whilst you [are] free and welcome to visit, please bear in mind that the land has been designated as a Site of Special Scientific Interest and a Special Area of Conservation.”
Jake Swindells, director of the Scottish Countryside Alliance, said the initial message was “completely at odds with the inclusive vision of responsible access to the countryside held by most people in rural communities”.
Helen Todd, campaigns and policy manager at Ramblers Scotland, said: “Rather than discouraging visits, Highland Titles should urgently revisit the Scottish Outdoor Access Code, which tells reserve managers to provide quality paths and information to help people avoid damaging or disturbing nature.”
Scottish Green MSP Ariane Burgess said: “Commodifying land as the exclusive pastime of those who can afford it, as Highland Titles seems determined to do, goes against the very essence of a green recovery and Scotland’s great tradition of the right to roam.”
Highland Titles previously attracted controversy over its selling of "souvenir" plots of land to "become a Lord, Laird or Lady".
It offers a number of packages on its website, from £30 for one square foot near Duror.
The website notes "you cannot buy a noble title" and it is "for enjoyment purposes only".
It also says Highland Titles “remains as the registered landowner”.
Highland Titles says its mission is to "fund the creation of multiple nature reserves throughout Scotland".
Chief executive Douglas Wilson told Scotland on Sunday: “There are not many organisations who have done more than we have to encourage people to visit and responsibly enjoy the great outdoors.
"As far as Glen Nant goes, we purchased this land last year and inherited the existing agreement with NatureScot, who will manage the land for the foreseeable future.
“As much as we'd like to encourage people to visit the land, NatureScot are worried about the effects that a greatly increased footfall may cause.
"People are absolutely free to visit the land if they wish, but we agreed at NatureScot's request not to actively encourage thousands of visitors to the area given that the land has been designated as SSSI and SAC.”
A spokeswoman for NatureScot said: “People are welcome to visit Glen Nant NNR [national nature reserve], a large part of which is managed by Forestry and Land Scotland which maintains the car park, footpaths and promotes responsible access to the site.”