RegDep
some data from (some?) ATC-related recordings obtained elsewhere than the Russian authorities
As I understand, Poles doesn't have anything that Rissan side doesn't have. They just claim that they will publish full transcript from all available tapes in ATC tower (1.11.7 of report), which Russians doesn't want to publish.
Also, they insist on geting information from mobile operators and ground lines which, as I think, MAK or doesn't posses or can't publish because of law restrictions.
BTW, MAK doesn't insist on full transcript of sattelite calls from plane and avoided to publish content of one mentioned in Report.