The affair has driven tensions between Russia and the West to new heights, with some Western governments believing Navalny was poisoned by Russian security services with top-level backing.
US Secretary of State Mike Pompeo said on Wednesday there was a "substantial chance" his poisoning was ordered by senior Russian officials.
Berlin faces calls for a sharper response to the poisoning.
Some opposition politicians have called for the Nord Stream 2 gas pipeline from Russia to Germany, a Kremlin flagship project, to be canceled, even as it nears completion.
Italian Prime Minister Giuseppe Conte was quoted on Thursday as saying Russian President Vladimir Putin had told him he would set up a committee to investigate Navalny's case and "was ready to collaborate with the German authorities".
(Writer: Thomas Escritt | Editors: Thomas Seythal, Timothy Heritage)https://t.me/kompascomupdate, kemudian join. Anda harus install aplikasi Telegram terlebih dulu di ponsel.