Single man inseminating 30 lesbians sparks incest fears in Australia

Unregulated sperm donation is leading to unusual situations in which the children of lesbians in Adelaide are mixing socially - creating a risk of incest.

One of South Australia's foremost experts in reproductive technology - Reverend Dr Andrew Dutney - says that in one reported case, about 30 lesbians were impregnated by sperm from one man.

The mothers then organised picnics with all the children, raising the fear they might socialise with their half-siblings without realising they are related.

In another case, a man's sperm was used to produce 29 children, most of whom are living in Adelaide. They do not know who their half-siblings are, raising concerns that in a "big country town" like Adelaide, they could accidentally commit incest.