What was found
ON TAXI IN, AFTER LANDING, THE CREW STARTED THE APU WITH A WAIT OF APPROX 2 MINUTES BEFORE MARSHALLER CAME TO THE GATE. DURING THIS TIME THEY RECEIVED A LAV SMOKE EICAS/BELL. THE A FA CALLED UP AND CONFIRMED IT AND INDICATED SHE CHECKED AND THERE WAS NO FIRE, BUT NOTED THERE WAS A HAZE/FILM IN THE CABIN. THE AIRCRAFT WAS PARKED AT THE GATE, THE JETWAY PULLED UP AND THE AIRCRAFT DEPLANED. DURING THE DEPLANING THE EICAS/BELL STOPPED. CREW REPORTED AN OIL TYPE SMELL IN THE CABIN. MAINT DETERMINED SMOKE CAME FROM OIL IN APU BLEED DUCT. OPS CK APU BLEED NORMAL.