AN A300-600R FLT CREW HAS SMOKE/FUMES IN CABIN; DECLARES EMER AND DIVERTS.

Narrative

APPROX 2 HRS INTO FLT ON AIRWAY ROUTES; FIRST INDICATION OF A PROB WAS THE FWD LAV SMOKE ALARM GOING OFF. FLT ATTENDANTS IMMEDIATELY CALLED COCKPIT TO INFORM US THAT THE CABIN WAS FILLING UP WITH SMOKE. DECLARED AN EMER. BOTH THE FMC AND ATC CONFIRMED THE CLOSEST ARPT TO BE ZZZ; WITH ANOTHER OPTION ZZZ1; BOTH AT 197 MILES AWAY. THE FLT ATTENDANTS RAN THEIR CHKLISTS AND STAYED IN COM AS THEY ATTEMPTED TO LOCATE THE SOURCE OF THE SMOKE. WE RAN OUR CHKLISTS AND COULD NOT DETERMINE THE SOURCE OF THE SMOKE. ON THE APCH TO ZZZ; A DEADHEADING MECHANIC CALLED THE COCKPIT ON THE INTERCOM AND SUGGESTED THAT HE THOUGHT THAT THE SMOKE SMELLED LIKE A BURNING PACK. AT ALMOST THE SAME TIME WE HAD A VERY BRIEF ECAM BLEED PAGE FLASHING ADVISORY; BUT ALL INDICATIONS APPEARED NORMAL. WE ELECTED TO TURN OFF THE #2 PACK AS IT WAS RUNNING HOTTER THAN #1 BUT WELL WITHIN NORMAL LIMITS. ON FINAL APCH; WHEN DISCUSSING THE NEED TO POSSIBLY EVACUATE WITH THE PURSER; SHE INFORMED US THAT THE SMOKE WAS DISSIPATING. OVERWEIGHT LNDG WAS SMOOTH; NO EVACUATION INITIATED AND NORMAL TAXI IN THE GATE.