Investigators are not linking last month's fatal loss of a UPS Boeing 747-400 freighter in Dubai to the recent discovery of explosive devices hidden in cargo consignments on the carrier's aircraft.
The United Arab Emirates' General Civil Aviation Authority insists that it has "eliminated" the possibility of an on-board explosion during the 3 September accident.
Both pilots on the 747 were killed after attempting to return to Dubai, the flight's departure point, after a fire alert and the spread of smoke into the cockpit while in cruise over Bahrain.
The GCAA states that its conclusions followed a "detailed on-site investigation" of the wreckage of the jet after it crashed and disintegrated outside of Dubai, as well as an examination of information from the cockpit-voice and flight-data recorders.
"There was no presence of acoustic evidence or any forensic signature supporting the detonation of an explosive device," it says.
It adds that it is still trying to establish the cause of the fire on board the aircraft. The US FAA drew up new procedures for handling lithium batteries - which had been part of the cargo - following the accident.
UPS suspended all services from Yemen following the discovery of an explosive device at East Midlands Airport in the UK which had been sourced from the Middle Eastern state.
A second device was discovered in Dubai after it was carried from the Yemeni capital Sana'a, via Doha, on board Qatar Airways services.
Qatar Airways has admitted that its aircraft transported the device, but stresses that the responsibility for inspecting and screening cargo lies with the state of origin, under the Chicago Convention.
"Furthermore, the explosives discovered were of a sophisticated nature whereby they could not be detected by x-ray screening or trained sniffer dogs," adds the carrier. "The explosives were only discovered after an intelligence tip off."
In a statement the UAE's GCAA says the package was seized at Dubai after authorities "grew suspicious" and laboratory tests subsequently confirmed that it contained explosives. The GCAA adds that it is "co-ordinating with competent authorities in other countries about the package and circumstances surrounding it".