German Chancellor Angela Merkel visits Kremlin critic Navalny in hospital

German Chancellor Angela Merkel paid a personal visit to Russian opposition politician Alexei Navalny while he was undergoing treatment in a Berlin hospital for poisoning.

"It was a personal visit to Navalny in hospital," Merkel's spokesman Steffen Seibert told a regular news conference, declining to disclose details of what was said or how long the meeting lasted.

The Kremlin critic wrote on Twitter that it was "a private meeting and conversation with the family". He added: "I am very grateful to Chancellor Merkel for visiting me in hospital."

Navalny was flown from Russia to Berlin last month after falling ill on a domestic flight. He received treatment in the Charite hospital for 32 days before being discharged last week.

According to the finding of German, French and Swedish experts, Navalny was poisoned with a nerve agent in Russia last month. But Moscow has so far rejected this.

Russia has repeatedly criticised Berlin for what Moscow says is a failure to share information on the case.

Navalny added: "I am very grateful to Chancellor Merkel for visiting me in hospital."

The Navalny case has further worsened relations between Moscow and a number of western countries. 

Merkel has faced calls to halt the nearly-completed Nord Stream 2 pipeline bringing Russian gas to Germany.