Russia has reported its second-highest number of new coronavirus cases and a record one-day death toll as the country's crisis continued to worsen.

There were 5,642 new cases reported on Tuesday, bringing the total from 47,121 to 52,763. That figure is second-only to 6,060 new cases recorded on Sunday.

Meanwhile another 51 people died from the virus, bringing the total from 405 to 456. it is the largest single-day toll so far after 48 deaths, also recorded Sunday.

The figures were released as a top government health official refused to rule out the possibility that coronavirus was manufactured in a lab and called for a 'thorough study' into its origins.

Russia reported 5,642 new cases of coronavirus on Tuesday, bringing the total number of cases to 52,763. It is the second-highest daily infection toll after 6,060 reported Sunday

Russia also reported 51 deaths from the virus on Tuesday, the highest one-day total of the crisis so far as the outbreak rapidly worsens

Russia announced 5,642 new cases of coronavirus on Tuesday and 51 new deaths, both record one-day tolls (pictured, a coronavirus ward in Pirogov City)

Veronika Skvortsova, head of Russia's Federal Medical-Biological Agency (FMBA) and ex-health minister, was asked if the pandemic virus could be artificial.

'This question is not that easy. It demands a very through study,' she said on Russia's Channel One. 'None of the versions can be ruled out.'

She said: 'We can see that a fairly large number of fragments distinguishes this virus from its very close relative, SARS.

'They are approximately 94 per cent similar, the rest is different… I think that we must conduct a very serious research.'

Even as Russia's crisis worsened, the Kremlin claimed to have cured the first three patients used blood plasma taken from people who had already recovered.

'We are hoping that the number of such recoveries will continue to grow, and that this method of treatment will help us cope with the coronavirus pandemic,' Moscow deputy mayor Anastasia Rakova said.

The treatment works by flooding an infected person's bloodstream with antibodies which fight the virus, taken from someone whose immune system has already beaten it.

A major search is underway for donors after 60 out of 1,679 recovered patients came forward in Moscow where there is a cash reward.

Russia now has a total of 52,763 cases of coronavirus and 456 deaths, as the country's outbreak accelerates after months where it performed better than the rest of Europe

A government worker sprays disinfectant at Savyolovsky Railway Station in Russia

Two people checked out after 10 days following blood plasma transfusion procedures at Sklifosofsky hospital in Moscow, and another after a fortnight at City clinical hospital number 52.

The number of Covid-19 cases cases in Russia began rising sharply this month, although it had reported far fewer infections than many western European countries in the outbreak's early stages.

Russia has carried out more than 2.1 million tests for Covid-19, according to official figures.

A total of 139,000 people remain under medical monitoring.

In Moscow, the authorities announced cash incentives to recovered coronavirus patients to donate blood plasma, offering £54 for a maximum per person 600 millilitres.

A major new Russian coronavirus hospital built from scratch on a greenfield site in 36 days has taken its first 20 patients.

The mammoth emergency £92 million complex will initially hold 800 patients - 300 more than originally announced - amid fears of the city's capacity being overrun.