In S01E01 Ashwathama of Sacred Games, when Sartaj witnesses Gaitonde committing suicide, he picks up a passport. The photo on it is visible, but I couldn't make out who that was. Then Katekar enters and he gives the passport to Katekar with "Do you believe in God?"
Whose passport was it and why was Sartaj astonished on seeing it. Is it mentioned anywhere in the series?