The site, in Worsbrough Wood, is covered by a preservation order and the local authority revealed work has continued, despite a planning application being refused by councillors in April.
Coun Tim Cheetham, cabinet spokesperson for place, said: “The area of Worsbrough Wood that has recently been developed sits within the green belt and the conservation area, and is covered by a tree preservation order.
“Development on the land is inappropriate and doesn’t benefit from planning permission.
“In 2018, we served an enforcement notice concerning the access routes that had been created, and we secured an injunction to prevent further damage to trees within the woodland.”
An application was made for the changing of the use of land to a gypsy site for the stationing of caravans for residential occupation - though this was subsequently refused following a review by Barnsley Council.
However work on the site continued to take place, forcing the council to issue a stop notice to the family.
“More recently, further enforcement notices have been served to prevent the use of the land as a gypsy and traveller site,” Coun Cheetham added.
“The notice also requires structures to be removed and for the land to be returned to its original condition.
“A stop notice was also issued, so we are extremely disappointed to see that work has continued on the site.”
The decision to refuse the planning application that was made by the Smith family came on April 15, following the public consultation months before.
The site is based on the land at the north side of Worsbrough Road, and is currently home to the unauthorised pitch.
Following the decision, made by the council’s planning team, the owner of the land did not accept the ruling, which led to the installation of concrete blocks to stop the use of access routes, but these were subsequently moved by the occupant.
“Given that the owner of the land has made no attempt to comply with the enforcement notice, we were in the process of installing concrete blocks to prevent the illegal use of the access routes,” Coun Cheetham said.
“However, we were appalled to learn that some of the blocks were purposely moved.
“We will continue with all necessary action until this case is resolved, the site vacated and the land restored to its previous condition.
“Further attempts to continue development or occupation of this site will be a waste of time and money for all involved.”