Building work that led to a 150-year-old bridge in Sudbury being damaged was unauthorised, according to council officers.
On November 13, a footbridge in Bridge Terrace was struck by contractors as they dug underneath the privately-owned structure, striking a gas pipe in the process and causing a power cut.
A subsequent inquiry by Babergh District Council has led to the project being deemed as unlawful, as it lacked the required planning permission to carry out engineering works.
The land owner, Chris King, had submitted an application for a one-and-a-half storey house on the former quarry site next to the bridge, but this has been deemed invalid.
District council planning officer John Davies said: “The application remains invalid as we are still awaiting information on land contamination issues and legal documentation relating to section 106 contributions.
“The ground works carried out by the developer are considered to be engineering operations, which constitute development and therefore require planning permission.
“Works carried out at the site by the developer are therefore unauthorised and have taken place at the applicant’s risk and wholly without our knowledge or approval.”
Mr Davies added that Mr King was told to stop work following concerns over the potential impact on the surrounding area, including slope stability and the integrity of the public footpath that runs alongside the site.
Officers acting for Suffolk County Council have since said they do not believe the footpath to have been damaged by the work.
Bridge Terrace resident Peter Hall and Sudbury tree warden Jill Fisher had complained that wildlife that formerly resided in the former quarry site, which had been used as an orchard, had been forced out when it was cleared.
But the district council has stated that any removal of vegetation did not require permission as the site was not a conservation area. It also confirmed that an environmental assessment study was never carried out.
Mr Davies, however, said: “That is not to say that the site, having been unused and over-grown for many years, is not a habitat for protected species and that the works carried out may have caused damage which cannot be undone.”
In response, and after pressure from Mrs Fisher, Sudbury town councillor John Sayers has suggested to the town council’s planning committee that it alerts the district authority to sites that it feels may be important habitats for wildlife so that environmental impact studies can be carried out in the future.