A data leak dubbed the Pandora Papers has revealed that powerful billionaires, as well as current and former world leaders, have been affiliated with companies that use offshore tax havens.
The investigation was carried out by the International Consortium of Investigative Journalists (ICIJ) and a team of 150 news outlets.
The 11.9 million documents revealed that 35 current and former heads of state as well as more than 330 politicians and public officials from almost 100 countries have assets in offshore accounts, secretive foundations or shell companies.
Offshore accounts are often used to manage large sums of money covertly to hide a person's true wealth.
One world leader named in the report is Czech Prime Minister Andrej Babis, who is facing parliamentary elections on Friday and Saturday.
According to the research, Babis purchased a 15-million-euro (17.4-million-dollar) tract of land in France in 2009 with no clear source for his funding.
According to the report, the payment for the land flowed through mailboxes in Washington, Monaco and the British Virgin Islands before reaching France. The 2009 purchase would have been made just at the time Babis was entering politics.
Babis denied the charges on Sunday, telling the CTK news agency it was clear that he neither did anything illegal or improper. He spoke of an attempt to "sully me and, in this manner, to influence the Czech parliamentary elections."
Babis has frequently played up his anti-corruption credentials as a politician. At the moment, according to a survey commissioned by CNN Prima News, Babis' ANO party is set to take 27.3 per cent of the vote in the upcoming election, which would make it the strongest party in the Czech parliament.
The ICIJ said the documents on which it based its report were provided by an anonymous source. They include documents from 14 tax havens and document transactions up to and including 2021.
Similar to the Panama Papers, the documents were reportedly leaked by an anonymous source. It is the biggest leak to date containing information on tax havens.
The Panama Papers came to the public in spring 2016 due to a data leak. They were documents from the Panamanian law firm Mossack Fonseca, which were evaluated by journalists around the world. They found that numerous politicians, athletes and other celebrities had assets in offshore companies.
The revelations put politicians, business people and celebrities under significant pressure.