A row over the sale of land near the final resting place of outlaw Rob Roy MacGregor has led to national park officials stepping up enforcement action at the site.

A number of plots were put up for sale at the Perthshire village of Balquhidder earlier this year, with the land – said to come with fishing rights - marketed as “the perfect retreat from the stresses and strains of a busy modern life”.

However, Loch Lomond & the Trossachs National Park Authority raised concerns about the way the ground was being described and warned that it is in an area at risk of flooding and would be unlikely to receive any planning permission.

The authority has now issued a temporary stop notice after unauthorised works were recently carried out on plots that have been sold, with no planning permission in place.

With further plots continuing to be marketed at auction, officials are again warning potential buyers to beware of buying sites which are not suitable for development.

Stuart Mearns, director of Place at the National Park Authority said: “We, along with the local community, are deeply concerned that work has commenced on this land.

“This development activity has not been authorised and is on an area of land which has a number of environmentally important qualities which mean it is unlikely to receive planning permission.

“Unauthorised development in a National Park is an extremely serious matter and we are taking urgent enforcement action by issuing a temporary Stop Notice. This requires all development activity to cease immediately. We are closely monitoring activity on this site. Further enforcement action is also being considered and steps will be taken if needed.

“What is also particularly worrying is that purchasers of the plots don’t appear to be aware of the sensitive environment or planning restrictions at this location. Plots on this land are still being marketed for sale without detailing the significant constraints of the site.

“Anyone purchasing these plots would be very unlikely to receive permission to develop them as they are in an environmentally sensitive landscape where there is a risk of flooding. We are keen to engage with those who have recently bought a plot here and to prevent anyone else from buying a plot without fully understanding these constraints.”

Future Property Auctions, who are selling the plots for between £8000 and £15,000, said they were not being marketed as development sites.

John Morris, general manager for the property firm, said they are being marketed for “those who are looking to own a piece land who enjoy fishing and the outdoors life”.

He added that, on recommendation from the local council, he has also included details that anyone looking to erect a structure would have to contact the council.

Rob Roy was buried in Balquhidder Parish Church in 1734 and spot’s history draws many visitors to the area throughout the year.

It is also an important environmental area which the park authority and locals believe needs to be protected.

David Johnston, chair of Balquhidder Community Council, said: “The residents and community of Balquhidder are extremely concerned about what is happening on some land near to Stroneslaney. Some of these new owners have started doing work without the necessary permissions and this is changing its nature and preventing the community and visitors from enjoying the recreational benefits they have enjoyed for years.”