Regulatory Audit: Sponsor Notification Requirements

Hello everyone,

I work at a CRO who performs viral safety tests. We are under GLP/GMP regulations. I am revising an SOP governing regulatory audit.

We currently have a section that states sponsors will be notified when regulatory inspectors are auditing a study and sponsor permission is required before inspectors can audit the study.

Two questions:

1. What are the regulatory requirements for sponsor notification? I couldn't find anything in the CFRs but wanted to ask my fellow auditors. We do work with both domestic and European companies.
2. I believe sponsor permission is unnecessary and sponsor notification is a courtesy. Awaiting sponsor permission (which could take days) is equivalent to denying access to raw data to a regulatory body.