MOSCOW -- Former Russian Deputy Prime Minister Sergei Prikhodko has died at the age of 64.
Media reports quoted Russian government officials and associates of the politician as saying that Prikhodko, who was also the former chief of the government administration, died on January 25 of an unspecified illness.
Earlier reports said that Prikhodko was diagnosed with a neurodegenerative disease known as amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease.
Prikhodko served as a top official and adviser on international issues at the presidential office from 1998 to 2012. He was named as a deputy prime minister in 2013, a post he held until 2018.
In early 2018 while deputy prime minister, Prikhodko was implicated in an investigative report by opposition politician Aleksei Navalny that suggested that Prikhodko, a longtime public servant with no significant private income, owned a luxurious mansion outside Moscow.
Another Navalny report revealed Prikhodko's ties with Kremlin-backed tycoon Oleg Deripaska. That report was largely based on the social-media account of a woman who claimed to have had an affair with Deripaska.
The woman, who called herself Nastya Rybka, posted several videos in 2016 showing Deripaska on his yacht near the Norwegian shoreline talking with Prikhodko.
Navalny cited public records to suggest that Prikhodko spent several days on the yacht and was flown there by Deripaska's private jet.
A year ago, Prime Minister Mikhail Mishustin appointed Prikhodko his aide.