Mining magnate Andrew Forrest has launched an organisation to end modern slavery, with the support of the Pope and the senior Islamic authority.

The Global Freedom Network has been inaugurated at the Vatican, and brings together the Catholic, Anglican and Sunni Muslim faiths in a combined effort to stop modern slavery.

Pope Francis, the Archbishop of Canterbury Justin Welby, and the senior Sunni authority, the Grand Imam of al-Azhar, are part of the leadership council.

The leaders of other faiths have been invited to join the network.

Speaking at the event, Mr Forrest said the campaign would spread to churches and mosques around the world.

"I ask, ladies and gentlemen, for your prayers now as the work of the Global Freedom Network in its unprecedented historical nature goes forward and does reach out successfully to the 162 countries which are measured in the Global Slavery Index," he said.

The Global Slavery Index, compiled by Mr Forrest's Walk Free foundation, estimates about 16 million people are enslaved in Pakistan and India alone.

In January, Mr Forrest announced a plan he said would free 2.5 million people from slavery in Pakistan.

Mr Forrest has signed a deal with the Pakistani state of Punjab that will give it access to Australian technology that can convert lignite coal into diesel.

He says Pakistan in return has agreed to bring in laws to tackle the problem of slavery or bonded labour.

Sorry, this video has expired Andrew Forrest speaks to ABC News 24

Mr Forrest said he was moved to act after meeting a nine-year-old Nepalese orphan who had been a victim of human trafficking.

"She looked at me with this look of abject terror - this horror, this disgust, this revulsion - and she screamed," he said.

"Since that time, Nicola, my wife, and I can't actually get that sound out of our heads.

"We committed ... to do something about it and that's when I came and ordered a full audit of Fortescue's supply chain and discovered slavery there as well."

The concept has won praise from former British prime minister Tony Blair, who described it as a great example of Australian philanthropy.

Mr Forrest had previously invested millions of dollars in Aboriginal employment initiatives in Australia and in 2012 founded Walk Free, a philanthropic charity focused on ending slavery worldwide.

He also helped to launch the Global Slavery Index, alongside Mr Blair and former US secretary of state Hillary Clinton, which found that 29 million people were living in conditions of modern slavery around the world.