Russia officially surpassed four million coronavirus infections Wednesday, days after the country dramatically revised upwards its fatality rate, cementing its place as one of the world's worst-hit nations.

A government tally showed infections had reached 4,012,710, which is the fourth-highest rate globally after the United States, India and Brazil.

But Russia has come under fire for its official virus statistics and the government's stated death toll of 78,134 in particular has been undermined by recent mortality data.

Figures published by statistics agency Rosstat on Monday showed more than 162,000 virus-related deaths last year, more than double the number reported by the government's task force so far.

Russia has frequently come under fire for downplaying the impact of the pandemic and only counting fatalities where coronavirus was found to be the primary cause of death after an autopsy.

The country had been battered recently by a second wave of infections but has held back on reimposing lockdowns like other European countries and instead relied on a nationwide vaccine rollout.

Russia said Wednesday that 2.2 million people in the country had been administered the jab since vaccinations began in January.

The mayor of Moscow Sergei Sobyain said last month that half of the city's population, or at least six million people, had been infected with the virus, suggesting a much higher nationwide toll.

Still, last month he also announced a significant easing of restrictions in the capital, which is the epicentre of the virus outbreak in Russia.

Bars and restaurants are operating as usual, schools have reopened and companies are no longer mandated to have staff work from home. Mask wearing in public is still mandatory.