A sperm donor has won parental rights to his biological son over the claims of the child’s lesbian birth mother, who is not the biological mother, in a landmark case in Australia.

The boy was conceived via IVF and the female couple chose donor eggs and donor sperm.

All parties were known to each other and the sperm donor, the child’s father, regularly spent time with the boy, including overnight stays.

The man said he agreed to the arrangement only on condition that he would be involved in the child’s life.

When the two mothers broke up, it triggered the messy 3-way custody battle.

The trial judge ruled that the father was not merely ‘a sperm donor’ as he had provided support and care to the boy, now 9, since the time of his birth.

‘(The mothers) do not enjoy any superiority over any other person keenly interested in (the boy’s) welfare, namely (the sperm donor).’

The birth mother, who lost her parental rights, had wanted sole responsibility of the child.

But the birth mother’s ex-partner, who had turned her life around following the breakup, fought for shared responsibility with the sperm donor father

The judge ruled the nine-year-old’s best interests meant giving shared responsibility to the birth mother’s ex-partner and the sperm donor father, leaving the birth mother out entirely.