According to newly leaked documents, an international civil society network headed by billionaire investor George Soros has given millions of dollars to organisations that are highly critical of Israel, including one that promotes boycotts and another that questions its right to exist.

A hack of the Soros-chaired Open Society Foundations by DC Leaks - the group that published copies of Hillary Clinton's emails earlier this year - revealed that the network had given nearly $10 million (£7.7m) to Adalah, I'lam and other groups that are critical of Israel.

Among the 2,500 files published by DC Leaks was a document in which Open Society Foundations said that one of its aims was to challenge "Israel's racist and anti-democratic policies".

According to another document, titled the Arab Regional Office Presidential Portfolio Review, the network has given $2,688,561 in 14 grants to Arab rights group Adalah since 2001.

Adalah describes itself as an "independent human-rights organisation" but has called on governments around the world to curtail their diplomatic ties with Israel.

I'lam, a Nazareth-based Palestinian media centre, has received $1,083,000 in nine grants since 2003, according to the documents. In a 2014 publication about the Nakba - the "catastrophe" of the creation of the state of Israel, according to Palestinians - I'lam accused Israel of ethnic cleansing and argued that "the practical meaning of the Nakba undermines the moral and ethical foundation of Zionism and, hence, of the state of Israel."

In the Arab Regional Office document, Open Society Foundations notes the success of Palestinian Citizens of Israel (PCIs) in challenging Israel's "racist" policies.

The document advocates the "development of a more organised and efficient PCI advocacy and presence in international forums (UN, EU, US)".

In a statement to news website JTA, Open Society said the documents focused on "big picture" strategies.

"The Open Society Foundations work with Israeli and Palestinian civil society organisations to support democracy and human rights in Israel and Palestine," it said. "We oppose human rights violations on all sides of the conflict and support implementation of international law."

Other hacked documents have revealed the extent of Mr Soros's influence on political affairs.

One email chain from 2011 shows a note from Mr Soros to then-Secretary of State Hillary Clinton, urging intervention in Albania’s political unrest. Within days, an envoy he recommended was sent to the region.

Mr Soros was born George Schwartz in Budapest. The 86-year-old former hedge fund investor survived the Holocaust by hiding with a non-Jewish family. After moving to the US, he began his career in Wall Street in the 1950s.