Russian authorities have stressed that they are willing to assist investigators with decryption of radar data submitted to the criminal probe into the loss of Malaysia Airlines flight MH17.
The Dutch national prosecutor had stated that the format of the Russian radar data was not that typically used in Europe for data exchange.
Russian federal air transport regulator Rosaviatsia says the primary data, which it transferred to the inquiry in October last year, is unprocessed, providing the most detail available on the situation at the time of the Boeing 777's destruction in July 2014.
This demonstrates the "authenticity" of the information, says Rosaviatsia, adding that transmission in the European format, known as 'Asterix', would have involved using already-processed data.
Rosaviatsia says the Dutch probe has taken three months to mention publicly the technical problems with extracting the radar data.
But it says that it is willing "at any time" to provide specialised developers familiar with decryption techniques, as set out by international co-operation procedures in the field of accident investigation.
Rosaviatsia says it is "committed" to an "honest, open investigation" into the crash of MH17 in eastern Ukraine.