Dear Gentleman,
I have already certified to OHSAS Lead Auditor by QSA (now merge as RABQSA) in year 2002 in Hong Kong. They have a selective on accredited program or non-accredited program. However, due to my past expereince, since I am the first person to be certified. I cannot find any other OHS auditor. Finally, two complete audits were supervised by experience IATCA (now change as IPC) Lead Auditor. RABQSA accepted the supervisor report. And RABQSA have already approved some Skill Examiner. You can ask the name list from RABQSA and looking forward the supervision in US. For IRCA, they have similar requirements but seem that you need other Lead Auditor Grade auditor be your supervisor.
Best Wishes,
Aldous