The names of thousands of offshore companies were published on Monday night as the Panama Papers were released in full.

It represented a massive trove of data on the finances of the rich and powerful, Nick Allen in Washington said.

The International Consortium of Investigative Journalists (ICIJ) made information fully available on 200,000 companies, trusts and foundations set up in 21 jurisdictions.

Data was obtained from Panamanian legal firm Mossack Foneca, which said it was hacked.

The release allowed members of the public to search networks of offshore companies including Mossack Fonseca's internal records of the true owners.

It excluded information and documents on bank accounts, phone numbers and emails.

The ICIJ said it was putting the information online "in the public interest".

Setting up an offshore company is not illegal and Mossack Fonseca said it observed rules requiring it to identify its clients.

But anti-poverty campaigners said shell companies can be used to shield money from taxation.

The data cache first emerged a month ago but the ICIJ has now decided to allow the public to search its database.

It showed offshore holdings of 12 current and former world leaders.

Previous reports based on the documents led to the resignation of Iceland's prime minister David Gunnlaugsson.