Investors interested in buying land in Africa have denied accusations that they are involved in land grabs, insisting their practice is the only way to feed growing populations.

Land in Africa, often extremely fertile and absurdly cheap, is the current talk of the investment market. The wealth funds assess issues to do with political volatility, risk of extreme weather, bribery and corruption.

One problem with the buy-up of Africa is that there is little oversight except from local governments and the investment funds themselves.

Al Jazeera's Laurence Lee reports from London.