Investigators examining the black boxes from the Ukrainian jet accidentally shot down by Iran have recovered its cockpit voice data, France's BEA accident investigation bureau said on Monday.
Iranian forces say they downed the Ukraine International Airlines Boeing 737 jet on Jan. 8 after mistaking it for a missile amid heightened tensions with the United States. All 176 people on board - including 57 Canadians - were killed.
"CVR data - including the event itself - has been successfully downloaded," the BEA said in a tweet, referring to the cockpit voice recorder.
It did not elaborate on the audio content, which records pilots' verbal communications and other cockpit sounds.
The release of any further information is a matter for Iranian authorities leading the investigation, a BEA spokesman said.
In June, Iran agreed to send the recorders to the BEA for analysis, ending a long standoff with Canada, Ukraine and France.
Canadian Foreign Minister Francois-Philippe Champagne said Iran's transfer was a much-needed and long-overdue step.
But he expressed doubt over an interim report by Iran's Civil Aviation Organization that blamed a misalignment of a radar system and lack of communication between the air defense operator and his commanders.
"I don't put much credibility into that report. It's not just the result of human error - I think that would be an oversimplification of what really happened," he told Reuters by telephone.
"We need to understand who the responsible people are, who gave that order, how could the airspace still be open, how were these missiles fired?"
The aircraft was shot down hours after Iran fired missiles at Iraqi airbases housing US forces in retaliation for the US drone killing of a senior Iranian commander.
The data extraction is being carried out with an Iranian investigator and observed by Canadian, US, Swedish and British experts and representatives from UIA, Boeing and engine maker Safran.