Locking down a service to a specific group or user role

Is there a way to lock down a service so it is not visible to anyone that isnt part of a certain group or user role? We would like to restrict this service from being viewable from the cases’ page. I have been able to restict the content of the case details page to only show content if you are member of that group but the cases are still viewable via the cases tab and therefore doesnt meet our requirements.

Any ideas or help appreciated.