Vladimir Putin has been left red-faced after a member of his family accidentally revealed figures for Russia's death toll in Ukraine.

Video shows Ana Tsivilyova, who is a deputy defence minister as well as reportedly a daughter of Putin's cousin, saying tens of thousands of appeals have been received by the Kremlin of people looking for missing soldiers.

She said: "The ministry of internal affairs takes (DNA samples) absolutely free of charge at its own expense, and enters into its database for all the relatives who have applied to us. I’ve already said 48,000."

The figure is well below those given by Western intelligence officials, whose estimates have ranged from 150,000 to 700,000 dead or badly wounded.

Russian opposition Telegram channel, Astra, shared the video footage of Tsivilyova, claiming it showed a parliamentary session last month.

After Tsivilyova revealed the figure, defence chief Andrei Kartapolov interrupted to remind everyone the numbers were top secret.

He said: "I earnestly ask you not to use these figures anywhere. This is such sensitive, closed information. And when we draw up the final documents, we should not include these figures anywhere."

Russia has seen more than 700,000 casualties since Putin's full scale invasion of Ukraine began in February 2022, according to the Ukrainian General Staff.

As of today (December 5), Kyiv's estimated total combat losses for Russia stand at 748,950, according to Ukraine's Defence Ministry.

Moscow has seen such a scale of casualties that it is "almost certain" to strain Russia's military medical system, according to Britain's Defence Intelligence organisation.

Neither Russia nor Ukraine publish casualty figures for their own side. Data from UALosses, which lists the names and ages of Ukrainian dead, puts Ukraine's recorded death toll at more than 65,000.

The average age of Ukrainian service personnel killed is 38.2 years, according to the UALosses website.

Russia saw its bloodiest month of the war in November, according to the Daily Telegraph, which said Putin's forces suffered 1,500 daily casualties.

Russian forces are pressing deeper into their western neighbour, with the front creeping westwards amid talk of possible peace negotiations and questions around the possibility of Ukraine joining the NATO military alliance.