Der Spiegel newspaper said that German Chancellor Angela Merkel visited Russian opposition politician Alexei Navalny while he was being treated in a Berlin hospital for poisoning, in confirmation of the seriousness that she takes to this issue.

The newspaper added, citing sources, that Merkel went to visit Navalny at the Charity Hospital, where he received treatment for 32 days after being flown from Russia to Berlin last month, after suffering fatigue during a domestic flight.

A spokesman for Merkel declined to comment on the report, and the German government says that tests conducted in Germany, France and Sweden found that Navalny was poisoned with the nerve gas called "Novichok", and demanded the Kremlin for an explanation.

Moscow denied any involvement in the incident and said it had not yet seen evidence of a crime.

Navalny left the hospital after recovering, and the German Hospital announced in a statement that the health condition of Navalny, 44, had improved to the point that he had ended his intensive medical treatment, which lasted for more than a month, mostly in intensive care, adding that a full recovery of the Russian opposition is possible.

The Kremlin welcomed Navalny's recovery, saying he could return to Russia as a Russian citizen, and asked whether Navalny would agree to meet with Russian investigators after his return to the country, and to provide information about what happened to him.