grammar - Present perfect and reported speech

I would like to understand the following (because Google returns suspiciously low number of records for this form):

A: I saw him there.
B (joins the conversation): Hey, have you seen John lately?
C: He has just said he had seen him there.

Is it OK to use present perfect and then reported speech shifted back (from past simple to past perfect)?

Answer

Present Perfect is OK with just (it points at the latest moment), but then you don't need Past Perfect: Past Simple is enough here to put the reported event before the event 'he has (said)'.