Some 35 current and former leaders and more than 300 public officials are featured in the files from offshore companies, dubbed the Pandora Papers.

*Ex UK PM Tony Blair and his wife saved 312,000 pounds in Stamp duty when they bought a London office,they bought an offshore firm that owned the building.

*Russian President Vladimir Putin's secret assets in Monaco

*Czech PM Andrej Babis failed to declare an offshore investment company used to purchase two villas for 12million pounds in the south of France

*Kenya President Uhuru Kenyatta and six members of his family secretly owned a network of offshore companies. They have been linked to 11 firms - one of which was valued as holding assets of $30m

• Members of Pakistan Prime Minister Imran Khan's inner circle, including cabinet ministers and their families, secretly own companies and trusts holding millions of dollars

The law firm founded by President Nicos Anastasiades of Cyprus appears to have provided fake owners to disguise the real owner of a series of offshore companies - a former Russian politician who had been accused of embezzlement. However, the law firm denies this

Ukraine's President Volodymyr Zelensky transferred his stake in a secret offshore company just before he won the 2019 election

Ecuador President Guillermo Lasso, a former banker, replaced a Panamanian foundation that made monthly payments to his close family members with a trust based in South Dakota in the US

The boy who owned a £33m London property

Mayfair building was sold to a front company in 2009

Other documents show how Azerbaijan's ruling Aliyev family have secretly acquired UK property using offshore companies.

The files show how the family - long accused of corruption in the European nation - bought 17 properties, including a £33m office block in London for the president's 11-year-old son Heydar Aliyev.

The building in Mayfair was bought by a front company owned by a family friend of President Ilham Aliyev in 2009.

It was transferred one month later to Hedyar.

The research also reveals how another office block owned by the family nearby was sold to the Crown Estate for £66m in 2018.

The Crown Estate said it carried out the checks required in law at the time of purchase but is now looking into the matter.

The UK government says it is cracking down on money laundering with tougher laws and enforcement, and that it will introduce a register of offshore companies owning UK property when parliamentary time allows.

The Pandora Papers is a leak of almost 12 million documents and files exposing the secret wealth and dealings of world leaders, politicians and billionaires. The data was obtained by the International Consortium of Investigative Journalists in Washington DC and has led to one of the biggest ever global investigations. More than 600 journalists from 117 countries have looked at the hidden fortunes of some of the most powerful people on the planet. BBC Panorama and the Guardian have led the investigation in the UK.