London: Sperm donors were handed the right to see and play a part in the lives of their biological children in a landmark High Court case on Thursday.

They may now also win the right to regular contact with the children, even though they are not bringing them up.

The ruling by the Family Division decreed that a sperm donor need never have had a sexual relationship with a mother in order to have a say in the child’s upbringing.

The judgement came in a complex dispute over parental rights between three gay and lesbian civil partner couples.

This case involved a donor who had previously known the mother of the children. However, the ruling leaves open the prospect that unprecedented rights for involvement in the lives of children may be granted to sperm donors who have little or no connection to the mothers.

The case threw fresh light on the agonising dilemmas that can be faced by the growing numbers of gay families.

Until now the law — set down five years ago in the Human Fertilisation and Embryology Act — has refused contact for sperm donors who have no other legal or domestic relationship with their biological children.

The case was brought by a gay sperm donor whose child is being brought up by a lesbian couple.

The Family Division ruling applies because the 2008 Act extended the law governing the rights of sperm donors to cover same sex couples.

The biological father and his civil partner were friends with two lesbian couples, both also in civil partnerships.

He is the father of two children of one of the lesbian couples. His civil partner is the biological father of a child being brought up by the other lesbian couple.

However, the agreement on paternity was struck informally between the friends and nothing about each couples’ duties and rights as parents was ever written down.

The arrangement between the couples broke down after the male couple applied to the Family Court for contact with their children.

The sperm donor in whose name the case was brought also asked for the children to live with him and his civil partner, but the court refused to consider this.

The female couples objected on the grounds that that contact would infringe their family life.

The Family Division judgement said that the family rights of the couples bringing up the children should be respected, but it said that courts must consider a sperm donor’s connection to his biological child.

Kevin Skinner, solicitor for the lesbian couple who must now offer contact to the biological father, said: “Although the judge’s decision makes clear that the family unit should be protected, the possibility of donors being able to apply for court orders will be a scary prospect for many parents, both gay and straight.

“What is crucial is that anyone planning on having a child through the use of fertility treatment should make sure that proper plans are in place before the process begins.”

Under current law, generally sperm donors can have rights and duties over a biological child — including a duty of financial support — if the family in which the child is being brought up has no father or mother to assume responsibility.