The world's finance ministers must use the G20 meeting in Sydney this weekend to crack down on tax avoidance by multinational corporations, Oxfam says.

It says national governments lose billions of dollars each year to tax loopholes and avoidance, and that money could be used to reduce developing countries' dependence on foreign aid and lift people out of poverty.

Dr Helen Szoke

Dr Helen Szoke, Oxfam Australia's chief executive, said the international tax regime was ''broken'' and needed fixing.