Russia's Federal Statistics Agency Rosstat said Friday that 44,265 people died of coronavirus in the country in September — double the official government figure.
That brings the agency's tally of Covid-19 deaths in Russia to nearly 450,000, the highest toll in Europe.
Russian authorities have been accused of downplaying the effects of the Covid-19 pandemic in the country and Rosstat's figure — released late Friday — painted a far darker picture than official figures suggest.
The number still fell short of Russia's monthly record of over 50,000 Covid fatalities in July, according to Rosstat.
An official government tally said Russia saw 24,031 deaths in September.
Government figures only take into account fatalities where the virus was established as the primary cause of death after an autopsy.
Rosstat, however, publishes figures under a broader definition for deaths linked to the virus.
Russia is the country hardest-hit in Europe by the pandemic, with authorities struggling to counter widespread anti-vaccine sentiment.
Despite pleas from President Vladimir Putin and the wide availability of the homegrown jabs, only 32% of Russians are fully vaccinated.
Moscow shut down non-essential services for 11 days on Thursday as the country battles a record-breaking virus surge, driven by the low vaccination rates.
Russia recorded 1,163 Covid deaths on Friday.
Putin has ordered a nationwide paid week off starting Saturday in an effort to curb the spread of the virus.