Each company bought a 12.5% stake in the Russian advertising giant in September 2003 for the same price – about $130,000 (£80,000) each.

The price paid was “ridiculous”, says Vladimir Milov, a former energy minister in President Putin’s first term and now a vocal opposition leader. “That stake was clearly worth much more, by many orders of magnitude.”

At the time of the purchase, Video International enjoyed a dominant position in the domestic TV advertising market, taking a cut of any advertising airtime purchased on Russian channels.

The company was “half a step away from the Kremlin administration”, according to Mr Milov.

Mr Abramovich had a stake in Video International for the next seven years. At one point, the company declared a turnover of “more than $2bn [£1.29bn]”. Dividends of $30m (£19.3m) were paid out to Finoto and Grosora over that period.

Video International reported revenues of $3bn (£1.9bn) in 2010. However, Finoto and Grosora each sold their investment that year for just $20m (£19.5m), a price that appears to be below its fair market value.

Finoto Holdings sold its stake to Med Media Network, a company nominally owned by Sergei Roldugin.

On the same day as the Finoto Holdings sale, the other Abramovich-linked company, Grosora Holdings, sold its 12.5% stake to Namiral Trading Ltd, a company later linked to Aleksandr Plekhov.

Putin’s ‘wallets’

Financial links between President Putin and Mr Roldugin were uncovered in 2016 as part of the Panama Papers, which involved the leak of millions of confidential documents from the Panama-based law firm Mossack Fonseca.

Mr Roldugin, along with Mr Plekhov, was at the centre of a suspected money-laundering scheme run by Bank Rossiya and some of President Putin’s closest associates. Bank Rossiya was sanctioned by the US government in 2014, which described it as “the personal bank for senior officials of the Russian Federation”.

Mr Roldugin told the New York Times at that time that he was not a businessman and did not “have millions”. However, at least on paper, he appeared to have an offshore fortune of over $100m (£61m).

“Rodulgin clearly serves… as a cover-up for Putin’s personal beneficial ownership,” says Vladimir Milov. “This guy is absolutely clearly 100% a nominal figure because he does not understand anything about business, finance, international transactions and so on.”

Revelations in the Panama Papers about bank accounts held by Mr Roldugin in Switzerland, led to an investigation and the trial of four Gazprombank employees earlier this year. The bankers were accused by Swiss prosecutors of failing to properly check accounts opened in the name of Roldugin.

They were also said to have failed to identify the Russian president’s friend as politically exposed – someone whose position or relationships mean that they may be more exposed to risks of corruption, and require more checks under international finance regulations.

According to the indictment, accounts with Gazprombank had been simultaneously established for both Med Media Network and Namiral Trading Ltd with an identical “purpose and structure” to “hold shares and receive dividends” from Video International.

The prosecutors said the arrangement represented a direct extension of “assets managed… for the Russian political establishment”.

Mr Roldugin and Mr Plekhov were “straw men”, and not the real beneficiaries of the accounts, the prosecutors alleged.

All four bankers were convicted, but are reported to be appealing.

The BBC wrote to Mr Plekhov, Mr Roldugin, Bank Rossiya and President Putin for comment but have received no response.

‘Secret conduit’

Many wealthy Russians have used Cyprus, an EU member state, as part of their network of offshore investments. Through these economic relations, Russia is “worth tens of billions of dollars to the Cyprus economy each year”, says Fergus Shiel of the ICIJ.

The Cyprus Confidential investigation raises “grave issues” for European institutions and EU member states, Shiel continues. “What we can see in these documents is a European member being a conduit for the secret financial operations of the Kremlin, of Vladimir Putin and his cronies.”

However, there are signs that Cyprus may be cleaning up its act.

Following the invasion of Ukraine in 2022, many Russians considered close to the financial assets of President Putin were sanctioned by the EU. This has had direct consequences for those with Cypriot investments.

“The sanctions brought home that Cyprus cannot be used by oligarchs to support the dirty orders of Putin,” says Alexandra Attalides, an independent Cypriot MP.

Meanwhile, reports suggest Mr Abramovich now spends his time between the Russian resort of Sochi, Istanbul and Tel Aviv. He has Russian, Israeli and also Portuguese passports.

The oligarch remains the subject of sanctions in the UK and EU, but not in the US, where he is understood to still hold considerable assets.