Cyprus has vowed to tighten controls on its financial sector as an investigation published by the Guardian and its reporting partners reveals oligarchs transferred hundreds of millions in assets while sanctions loomed after the Russian invasion of Ukraine.

The largest ever financial data leak from Cyprus also sheds light on how opaque offshore structures managed by accountants and corporate service providers in the EU member state may have enabled undisclosed payments to an influential western journalist, and potential breaches of rules around football club financing.

In response to detailed questions from the consortium, a spokesperson said Cyprus was receiving technical support from the British government to create a sanctions implementation unit next year, with plans to be submitted this month alongside a report on how its authorities investigate and prosecute financial crime.

Undisclosed agreements that allowed Abramovich and the super-agent Pinhas Zahavi to control the careers of 21 young footballers under controversial third-party ownership arrangements, which have been compared to bonded labour.

The leaked documents, which date from the mid-1990s to April 2022, show nearly 800 companies and trusts registered in tax and secrecy havens that were owned or controlled by Russians who have been placed under sanctions since 2014, when Russia annexed Crimea.

Nikos Christodoulides, a career diplomat who was elected president in February of this year, has led efforts to bring the financial services sector into line after decades of lax regulation.

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