"From the very beginning, Russia has been offering to take part in the investigation into the incident. But Moscow's desire has been ignored, and Moscow is deprived of the opportunity to receive any materials," Kremlin spokesman Dmitry Peskov said on Monday.
In the meantime, he added that Moscow would not comment on media reports on the issue, as they were based purely on allegations.
"We will no longer engage in discussions with media outlets. The BBC could not confirm anything; the BBC could only make an assumption or something else. And because the whole controversy is evolving in media, we, as the Kremlin, do not want to take part in this discussion any longer," Peskov told reporters
Russia has repeatedly offered to help in the UK’s investigation of the case; the Russian Foreign Ministry has sent some 60 diplomatic notes to the UK Foreign Office in order to get access to the probe. However, British authorities have not wished to cooperate with Russia, leaving those notes unanswered.