Police fear a trio of female 'sperm collectors' are on the loose in Zimbabwe after they picked up a hitchhiker on a highway and raped him in order to 'harvest' his sperm.

The women, believed to be driving a white Toyota Cresta, offered him a lift along a main road in the city of Bulawayo, in the country's southwest.

But partway through the journey the women attacked him - forcing him to have sex with them and making off with his semen.