Alexander Murakhovsky, the doctor who first treated Kremlin critic Alexei Navalny after he collapsed on a flight in Russia last year, has disappeared, Russian police said on Sunday.
The physician was last seen leaving a hunting base in a forest in the Omsk region — around 2,200 km (1,370 miles) east of Moscow — in an all-terrain vehicle on Friday, police said. He was reported missing the following day.
A search effort, including emergency services, drones, a helicopter, and volunteers on the ground, resumed on Monday morning after being suspended the previous night.
"So far I have nothing to add to what we posted yesterday (Sunday). All I can say is that the search has resumed at dawn," Russia's Ministry of Internal Affairs said.
The doctor was promoted to the position of regional health minister last November.
What role did the doctor play?
Murakhovsky was the head doctor at the hospital that Navalny was taken in late August 2020 after he fell violently ill during a domestic flight from Siberia to Moscow.
Navalny was eventually allowed to be airlifted to Germany for further treatment after tense negotiations with authorities.
Murakhovsky had said that initial laboratory tests after treating Navalny had not shown traces of the Novichok nerve agent.
Tests by laboratories in three European countries, confirmed by the international chemical weapons watchdog OPCW, determined that the Soviet-era poison had in fact been used on the opposition figure.
The Kremlin has denied accusations of being behind the attempted killing of one of President Vladimir Putin's main political opponents.
Navalny continues to be a problem for the Kremlin
Navalny was arrested in February after returning to Russia from Germany on what he has called trumped-up charges.
The treatment of the political activist, as well as his supporters, by Russian authorities, has triggered an international outcry and calls for Navalny's release.