The licence allowing the concreting of the cliffs and filling of caves at Whipsiderry Beach has been revoked.
Several rockfalls have occurred at the site since work began on the cliffs in preparation for a holiday homes development at the top.
The Marine Management Organisation (MMO) cited a change in circumstances due to "significant" rockfalls, which have altered the beach profile and landscape. The MMO stated that "some information provided during the original determination is no longer applicable."
In its determination, the government body noted that it could not rule out a potential link between the rockfalls and the licensed activities. To protect the environment and public health from further rockfalls, it concluded that halting the licensed works was necessary.
The campaign group Save Whipsiderry Cliffs welcomed the decision, describing it as a positive step. However, the group criticised the MMO for "wiping their hands and stepping away" and "leaving a mess that they are partly responsible for."
The group has pledged to prioritise reopening public access to the beach. Landslides led Cornwall Council to close the access steps, initially with temporary fencing. Earlier this year, a fixed gate and fence were installed to prevent public use of the steps.
Radio Newquay has contacted the developer, Living Quarter Properties, for comment.