Iran will send the black box flight recorders from the Ukrainian jetliner that it accidentally shot down to Ukraine for further analysis, officials in Tehran said.
Hassan Rezaeifer, the head of accident investigations for the civil aviation department, said it was not possible to read the black boxes in Iran.
He told an Iranian news agency that French, American and Canadian experts would help analyse the recorders in the Ukrainian capital.
Mr Rezaeifer added if that does not work, the black boxes will be sent to France.
Iran’s Revolutionary Guard say they accidentally shot the plane down shortly after it took off from Tehran on 8 January, killing all 176 people on board.
Hours earlier, the Guard had launched ballistic missiles at US troops in Iraq in response to the US air strike that killed Iran’s top commander, General Qassem Soleimani.
Officials say lower-level officers mistook the plane for a US cruise missile.
Iranian officials initially said the crash was caused by a technical problem and invited countries which lost citizens to help investigate.
Three days later, Iran admitted responsibility after Western leaders said there was strong evidence the plane was hit by a surface-to-air missile.
The victims included 57 people from Canada, as well as 11 Ukrainians, 17 people from Sweden, four Afghans and four British citizens.
Most of those killed were Iranians.
The plane was a Boeing 737-800 that was designed and built in the US.
The plane’s engine was designed by CFM International, a joint company comprising the French group Safran and US group GE Aviation.
Investigators from both countries have been invited to take part in the probe.
Cover image: Wreckage at the site of a crash of an Iranian Boeing 737 jet about 30 miles south of Tehran on 8 January (Picture: PA).