Two men and a woman involved in a polyamorous relationship can all be considered as the legal parents of a child born within the unconventional family, a Canadian court has ruled.

According to the Financial Post, Justice Robert Fowler of the Newfoundland and Labrador Supreme Court (Family Division) recently ruled that the three adults were entitled to be the legal parents of the child born to the woman within the three-way relationship in 2017.

Fowler said in the introduction of his ruling that the two men - identified only in court documents as J.M. and J.E. - and the woman - identified only as C.C. - have been involved in the polyamorous relationship since June 2015.

"None of the partners in this relationship is married and, while the identity of the mother is clear, the biological father of the child is unknown," he wrote, as reported by the Financial Post.

The lawsuit was filed by the three adults seeking to be recognized as the parents of the child after the Newfoundland Ministry of Service insisted that only two people can be listed on the child's certificate.

Fowler contended that he considered the best interests of the child in his ruling and determined that the child was being raised in a stable family that had been able to provide a nurturing environment.

"To deny this child the dual paternal parentage would not be in his best interests. It must be remembered that this is about the best interests of the child and not the best interest of the parents," the judge wrote, according to Financial Post.

A Canadian court previously ruled that three people could be recognized as legal parents in a case involving two women and a man who were not in a polyamorous relationship.

In the 2007 case, the Ontario Court of Appeal ruled that the two women in a relationship could be considered as the mothers of a child, while also recognizing the biological father as a legal parent.

Toronto-based lawyer Adam Black said that the impact of the Newfoundland case will be demonstrated when people involved in polyamorous relationships separate.

"How do we use the current model to resolve the issues that arise when there are three parents, particularly with respect to issues of property and support – the financial side of the breakdown?" Black said, as reported by The Canadian Press. "For me, this is very much uncharted waters. It's a new frontier in family law," the lawyer added.