Australia's big four banks are financing companies in developing countries that are accused of forcing people off their land, according to Oxfam Australia. In a report issued today, Oxfam claimed to have evidence  that all of the big banks have backed companies that contributed to illegal logging, forced evictions, food shortages, inadequate compensation and child labour.Oxfam said the banks were unaware of, or failing to respond to, the ethical risks of doing business in the developing world, particularly when it comes to funding the agricultural and timber industries.Oxfam said the World Bank and some large corporations, such as Coca-Cola and PepsiCo, had recognised these issues and acted on them.The report said that Westpac was supporting a timber company in Papua New Guinea that was logging pristine rainforest in defiance of an explicit finding by PNG's Commission of Inquiry into Special Business Leases that its lease was invalid and should be revoked.Among Oxfam's other findings: ANZ is financing a sugar plantation in Cambodia that has involved child labour, military-backed land grabs and food shortages; Commonwealth Bank has invested in an agribusiness company whose Brazilian sugar mill is sourcing material from people occupying land in defiance of Brazilian law; and NAB has been funding a palm oil company, Wilmar, which has been linked to land grab allegations.Oxfam has called on the banks to properly investigate and report on their exposures to unethical and illegal business practices, and make a commitment to "zero tolerance" of land grabbing.