Scientists have genetically modified a fungus so that it can kill mosquitoes as part of a new drive to fight malaria.

The trial in Burkina Faso – which was conducted in a sealed model village – killed more than 99 per cent of 1,500 mosquitoes and is being hailed as a “big step” forward by the study's authors.

However, critics are concerned that the genetically modified fungus could impact other insects and even animals.

“Fighting malaria through genetic engineering is dangerous” Nnimmo Bassey of the Health of Mother Earth Foundation, an advocacy group based in Nigeria, told NPR.

“I'm heavily worried that Africans are the preferred guinea pigs for experimentation, and Africa is going to become a large laboratory for risky experimentation.”

The experiment was conducted by scientists from the University of Maryland (UMD) in the US and the IRSS research institute in Burkina Faso and its findings published this week in the journal Science.

They took a naturally occurring fungus, Metarhizium pingshaense, and combined it with the DNA of a venomous Australian Blue Mountains funnel-web spider. While the fungus does kill mosquitoes in its unaltered state, when combined with the new spider genes it becomes far more deadly and fast-acting.