Allegations of child sexual abuse are being increasingly invented by mothers to stop fathers from seeing their children, says a retiring Family Court judge.

Justice David Collier, retiring from Parramatta Family Court at the end of the month after 14 years on the bench, sees unprecedented hostility infiltrating the Family Court, and a willingness by parents to use their children to damage one another.

Rise in hostility: Justice David Collier. Credit:Sahlan Hayes

''If a husband and wife really get down to it in this day and age, dirt flies,'' Justice Collier said.

The worst are those mothers who direct false allegations of abuse against former partners.