The notices were issued after a panel of five judges submitted a report to acting Chief Justice Jayant Patel, citing irregularities in the appointments.
According to the notice sent to the 94 staff members, the appointments were made without issuing public advertisement.
"...Your appointment which is purely temporary in nature is liable to be terminated at any time....However, in accordance with the principles of natural justice, you are given an opportunity to show cause," said the notice issued by Registrar General B N Karia.
City-based RTI activist Ajay Prajapati had last month filed an affidavit before the High Court saying that due process was not followed and several rules were flouted by the High Court administration in recruiting class IV employees.
Relatives of judges, staff attached to them were appointed in some cases, he alleges.