The Kremlin says it sees no need for now to investigate the circumstances leading up to opposition politician Alexei Navalny’s grave illness and that a German clinic’s initial diagnosis of poisoning is not yet conclusive.

German Chancellor Angela Merkel on Monday called on Russia to investigate the suspected poisoning and to hold the perpetrators accountable after German doctors found indications of a toxic substance in his body.

But Kremlin spokesman Dmitry Peskov said on Tuesday the German clinic had not conclusively identified the substance behind Mr Navalny’s illness and that it was unclear why German doctors were “rushing” to use the word poisoning.

“There must be a reason for an investigation. For the moment, all you and I see is that the patient is in a coma,” Mr Peskov told reporters on a conference call.

Kremlin dismisses accusations that Russian President Vladimir Putin sanctioned poisoning of critic Alexei Navalnyhttps://t.co/YLKhlGM2yT

— BBC News (World) (@BBCWorld) August 25, 2020

He added that if poisoning was definitively established as the cause, then an investigation would be launched.

“If the substance is identified and it is determined it was a poisoning, then, of course, this will be a reason for an investigation,” Mr Peskov said.

Demands for a probe are intensifying, with Sweden’s Foreign Minister Ann Linde on Tuesday saying on Twitter that the “circumstances regarding the suspected poisoning of @navalny need to be clarified by independent investigation.”

Late on Monday, top European Union diplomat Josep Borrell also asked Russia to investigate.

The circumstances regarding the suspected poisoning of @navalny need to be clarified by independent investigation. Important for his family, Russia and the international community. https://t.co/fyf4QxWmtr

— Ann Linde (@AnnLinde) August 25, 2020

Mr Navalny, an outspoken opponent of President Vladimir Putin, was airlifted to Germany for treatment on Saturday after collapsing on a plane while flying back to Moscow from Siberia.

German doctors treating Navalny at a Berlin hospital said on Monday that medical examinations indicated poisoning with some kind of cholinesterase inhibitor, although the specific substance is not yet known.

Russian health officials contradicted that diagnosis, saying Mr Navalny had tested negative for cholinesterase inhibitors when he was hospitalised in Omsk last week.

Peskov said doctors at the Omsk hospital had battled for three days to treat Mr Navalny and had possibly saved his life.

“We don’t understand why our German colleagues are rushing with the word poisoning,” he said.

Mr Navalny has been a thorn in the Kremlin’s side for more than a decade, exposing what he says is high-level graft and mobilising protests.

Reported to be under ‘intensive surveillance’, he has been repeatedly detained for organising public meetings, sued over corruption investigations and barred from running in the 2018 presidential election.

Mr Peskov said any suggestions that Mr Putin was somehow involved in Navalny’s illness was “hot air”, which the Kremlin would not take seriously.

Germany said on Monday Mr Navalny was being guarded due to concerns for his safety.

Mr Navalny’s wife, Yulia, was filmed entering the hospital on Tuesday but declined to speak to journalists.

-AAP