As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW PERFORMED AN ATB AT FL130 DUE TO THE F/A REPORT OF HAZE IN AFT CABIN. ACCOMPANIED BY THE AFT LAVATORY SMOKE DETECTORS SOUNDING. MAINTENANCE INSPECTED ENGINES AND APU FOR OIL LEAKS. NONE FOUND. PERFORMED DUCT BURNOUT PROCEDURE TWICE. NO FURTHER FUMES OR SMOKE PRESENT. ACFT HAS RETURNED TO SERVICE.