An attached photo is of freelance journalist David Stern, who is based in Kiev and has reported for the BBC on events in Ukraine. The other is supposed to be a David Hamilton who works as an international affairs consultant and an adviser to USAID, a US website reported.

"Hello. How are the preparations?" the voice identified as Hamilton opens the call said to have been made on June 25, 2014, about three weeks before MH17 was shot out of the sky by what investigators have widely suspected was a Russian-made ground-to-air missile.

"Everything is according to plan," answers "Stern" in British-accented English.

In the series of six recordings allegedly intercepted between the two men said to be CIA agents, they refer to orders from their leaders to implicate pro-Russia separatists in the plane's destruction – a scenario Russia's state-run media have put forward since the July 17, 2014, crash of MH17 in which all 298 on board were killed.

"If you wanted to believe the CIA is responsible for downing MH17, now you've got the 'proof,'" the self-exiled Russian online newspaper Meduza headlined its report pointing out the awkward language used by the purported spies.