The World Council of Churches has invited its members to join a global call to action against corruption – which impacts poor people the most.

Studies have shown that every year more than one trillion U.S. dollars go missing from the global economy through bribes, dishonest deals and tax evasion, the WCC said in statement Tuesday.

"The WCC's concern and response to the issue of corruption is founded on God's preferential option for people in poverty," said Rev. Olav Fykse Tveit, the WCC general secretary.

"Corruption is rooted in and propagated by our prevailing economic structures, cultures and value systems" which he said are driven by "greed, relentless pursuit of power, profit and material gain by corporations, political bodies, administrators and individual actors. "

The WCC is focussing on October 14 to 20, the global call to action EXPOSED 2013 will engage people around the world in raising their voices against corruption which has much greater media attention since the global financial meltdown of 2008.

Separate from the WCC campaign, Sudanese-born philanthropist Mo Ibrahim said Africa has a serious deficit in leadership and he noted that South Africa needs to step up and play a better role in the continent.

Ibrahim was delivering the annual Nelson Mandela Lecture in Pretoria on Saturday and he like many other African leaders believe that corruption stemming from within and outside Africa stifles development in one of the world's biggest, but poorest continents.

"Leadership is not about bossing people around...it is not about securing a seat in the UN Security Council on behalf of Africa, or chairing the African Union," he said.

"Leadership is true engagement with Africa. You [South Africa] have a role to play."

Problems such as climate change, transparency, tax evasion and illicit transfers of funds needed the serious voice of leadership.

Ibrahim is a communications entrepreneur and billionaire and he Ibrahim set up the Mo Ibrahim Foundation to encourage better governance in Africa, as well as creating the Mo Ibrahim Index, to evaluate nations' performances.

For his part, Tveit said that confronting systemic corruption is "a matter of upholding God's justice."

MICAH CHALLENGE

The initiative is organized by a coalition of Christian organizations known as the Micah Challenge International.

The campaign offers suggestions for positive and practical engagements of resisting corruption. It aims to hold 2000 vigils with the poor across the globe, while collecting one million signatures for the campaign and presenting a million more at the G20 meeting set to take place in Russia in November 2014.

The WCC general secretary called EXPOSED an "important effort" which he said correlates to the WCC's engagement with the churches in their struggles against economic injustice.

The WCC's programme on poverty, wealth and ecology deals with issues related to just trade, ecological debt, overcoming greed, decent work and efforts of seeking alternatives to globalization.

The meeting of the WCC's highest governing body, its assembly,from October 30 October to November 8 in Busan, South Korea will hold a special meeting on overcoming greed.

The WCC together with World Communion of Reformed Churches, Council for World Mission and the Lutheran World Federation will hold an international panel on New Financial and Economic Architecture from August 23 to 25 near Geneva.

The meeting will develop advocacy strategies on how to overcome greed while working towards a new economic and financial architecture.