A huge new leak of financial documents has revealed how the powerful and ultra-wealthy, including the Queen's private estate, secretly invest vast amounts of cash in offshore tax havens.

Donald Trump's commerce secretary is shown to have a stake in a firm dealing with Russians sanctioned by the US, BBC reported.

The leak, dubbed the Paradise Papers, contains 13.4m documents, mostly from one leading firm in offshore finance.

BBC Panorama is part of nearly 100 media groups investigating the papers.

As with last year's Panama Papers leak, the documents were obtained by the German newspaper Suddeutsche Zeitung, which called in the International Consortium of Investigative Journalists(ICIJ) to oversee the investigation. The Guardian is also among the organisations investigating the documents.

Sunday's revelations form only a small part of a week of disclosures that will expose the tax and financial affairs of some of the hundreds of people and companies named in the data, some with strong UK connections.

Many of the stories focus on how politicians, multinationals, celebrities and high-net-worth individuals use complex structures of trusts, foundations and shell companies to protect their cash from tax officials or hide their dealings behind a veil of secrecy.

The vast majority of the transactions involve no legal wrongdoing.

Other key stories being released on Sunday are:

• A key aide of Canada's PM has been linked to offshore schemes that may have cost the nation millions of dollars in taxes, threatening to embarrass Justin Trudeau, who has campaigned to shut tax havens.
• Lord Ashcroft, a former Conservative party deputy chairman and a significant donor, may have ignored rules around how his offshore investments were managed.
• Other papers suggest he retained his non-dom status while in the House of Lords, despite reports he had become a permanent tax resident in the UK.
• How questions were raised about the funding of a major shareholding in Everton FC.
• The papers suggest oligarch Alisher Usmanov may influence due diligence checks on his own firms.

The other media partners may be covering different stories affecting their regions.

How is the Queen involved?

The Paradise Papers show that about £10m ($13m) of the Queen's private money was invested offshore.

It was put into funds in the Cayman Islands and Bermuda by the Duchy of Lancaster, which provides the Queen with an income and handles investments for her £500m private estate.

There is nothing illegal in the investments and no suggestion that the Queen is avoiding tax, but questions may be asked about whether the monarch should be investing offshore.

There were small investments in the rent-to-buy retailer BrightHouse, which has been accused of exploiting the poor, and the Threshers chain of off-licences, which later went bust owing £17.5m in tax and costing almost 6,000 people their jobs.

The Duchy said it was not involved in decisions made by funds and there is no suggestion the Queen had any knowledge of the specific investments made on her behalf.

The Duchy has in the past said it gives "ongoing consideration regarding any of its acts or omissions that could adversely impact the reputation" of the Queen, who it says takes "a keen interest" in the estate.

Embarrassment for Ross and Trump?

Wilbur Ross helped stave off bankruptcy for Donald Trump in the 1990s and was later appointed commerce secretary in Mr Trump's administration.