An official Russian investigation into the death of Kremlin critic Alexei Navalny was redacted to remove any indications of possible poisoning, The Insider reported Sunday, citing “hundreds” of documents it said it had obtained. Navalny’s widow revealed last month that she received a letter from Russian investigators claiming there were no signs of foul play in her husband’s death at an Arctic penal colony in February. The letter stated that no toxic substances were found in his body, attributing his death to “a range of illnesses.” However, The Insider published what it claims is the unredact…