I did not find on the forum the name of Ivan Manukhin. He was a doctor. Supporting the February Revolution, he treated Gorky. He later worked with monarchist prisoners at St. Peter and St. Paul fortress, including Anna Viroubova. I think he makes the link between Gorky and Mrs. Viroubova (see the memories of Mrs. Viroubova)
He left (brief) memories of his work during the revolution. I put the link. It's in Russian.
http://rulife.ru/mode/article/11/