Hi, hope you can help me!

Many years ago I saw a spy movie.  There were eight or more spies and one was a mole / traitor, but they couldn’t figure out which of them was the mole.

So they decided to make one of them a central repository of information in the hopes that they could find the mole.  This central figure would wear a hood or a mask of some kind to hide their identity from the ofhers, and was known as “The Oracle”.  Then they used some (manual) system, e.g., “draw a card”, and one card was marked “oracle” to anonymously choose which spy would be The Oracle.

Sorry, I can’t remember how it ends.

I do remember seeing each of the spies tell their information to The Oracle.  The plot was fascinating.

Iirc, I watched this movie before 1980.

Please help!  And thanks in advance.