PARIS (Reuters) – 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.

Iranian forces say they brought down the Ukraine International Airlines (UIA) jet, a Boeing 737, on Jan. 8 after mistaking it for a missile amid heightened tensions with the United States. All 176 people aboard Flight PS752 were killed.

“CVR data – including the event itself – has been successfully downloaded,” the BEA said in a tweet on Monday, referring to the cockpit voice recorder from the downed jet.

The BEA did not elaborate on the content of the audio, which records the 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.

The data extraction, expected to take most of this week, is being carried out with an Iranian investigator and observed by Canadian, U.S., Swedish and British experts and representatives from UIA, Boeing and engine maker Safran.

Iran agreed in June to send the black boxes to the BEA for analysis, ending a long standoff with Canada, Ukraine and France over access to the data. Work began early on Monday at BEA headquarters outside Paris.

Many of the crash victims were Canadian citizens or permanent residents, or had Canada as their final destination.

An interim report by Iran’s Civil Aviation Organisation last week blamed a misalignment of a radar system and lack of communication between the air defense operator and his commanders for the tragedy.

Ukrainian President Volodymyr Zelenskiy said on Monday he welcomed Iran’s decision to hand over the black boxes, saying those responsible would be held accountable.

(Reporting by Laurence Frost; Editing by Mark Heinrich)