The Health and Safety Executive (HSE) has ruled out an internal inquiry after it was criticised by an Industrial Tribunal.
Both Limavady-based Bridgeline Demolition and Bridgeline Environmental Services and the HSE were last week rapped by the panel following asbestos contamination at a site in Carrickfergus last July.
The tribunal said: "It seems extraordinary to us that having a risk of serious personal injury...the HSE took absolutely no steps to minimise the risk until this tribunal expressed its disquiet and concern."
It also hit out at Bridgeline for not making approaches to HSE to "suggest appropriate remediation work".
But in a statement HSE told the Belfast Telegraph: "Whilst there will be no internal inquiry, HSENI has considered the criticism levelled at it by the tribunal. HSENI's role is to 'police' the standard of compliance with health and safety regulations by others and, if appropriate, take enforcement action.
"The risk at the site was created by Bridgeline Environmental Services Limited and its sister company Bridge Line Demolition Limited. They had prime responsibility for the clean up.
"In this case the contractor was very slow to prepare the necessary method statement detailing how the site clean up would be conducted. When HSENI was eventually provided with this document in September it gave approval within hours and did not delay the clean up."
HSE has also declined to rule out the possibility of a criminal prosecution in the case. It said: "This ruling does not preclude criminal prosecutions being taken against the parties concerned. Any decision as to whether or not to take criminal proceedings rests with the Public Prosecution Service for Northern Ireland (PPSNI)."