A new report states that a rare toxin found on the skin of a South American frog species was found in the body of deceased Russian opposition leader Alexei Navalny.

German Foreign Minister Johann Wadephulhas called for consequences, saying that Navalny's death was "a severe blow to all those — especially in Russia — who have not abandoned hope of a free country."

DW News asked biochemist Marc-Michael Blum how credible he found the report.