The Exposed campaign has welcomed a new global initiative to investigate companies and individuals suspected of tax evasion.
The UK Government announced recently that it is working with tax authorities in the US and Australia to share information and identify those suspected of using off-shore tax havens in places like the Cayman Islands to hide income and assets.
Investigations will also look at the role of tax advisers, accountants and lawyers in setting up offshore tax structures.
It it estimated that the UK alone loses £70 billion a year in revenue as a result of tax evasion.
The Reverend Joel Edwards, international coordinator of Exposed, a Christian campaign to expose corruption, quoted suggestions from Christian Aid that illegal tax evasion could be responsible for the deaths of 5.6 million children in developing countries between 2000 and 2015.
He welcomed the new collaboration between the UK, US and Australia to identify those using offshore tax systems to conceal their true wealth from tax authorities back home.
"Corruption is one of the main causes of poverty across the world, but it's not just about greed, the abuse of public influence, bribery, or even secret and dishonest deals," he said.
"Deliberate tax evasion is also a form of corruption because it results in money lost to an economy – resources which could and should be used to share the load of people living in dire poverty.
"Only through global co-operation on this level are we going to be able to understand the extent of corruption which we are facing and to challenge those in power to understand their responsibilities."
Exposed is asking G20 nations to clamp down on tax evasion by introducing measures requiring businesses to reveal the taxes they pay in all jurisdictions.
The campaign aims to gather a million signatures in support of its Global Call to End Corruption this year. The petition will be handed to the G20 leaders of the world's leading economies in 2014.
A Week of Action, including vigils for the poor, will take place this year from 14 to 20 October 2013.