A US federal judge has struck down a Kentucky ban on the recognition of same-sex marriages from other states.

US District Judge John G Heyburn ruled that the ban violated the guarantee of equal protection under the US Constitution.

He joined nine other federal and state courts which have made similar rulings.

The lawsuit was brought against Kentucky by four gay and lesbian couples who married out of Kentucky.

Judge Heyburn ruled that while “religious beliefs … are vital to the fabric of society … assigning a religious or traditional rationale for a law does not make it constitutional when that law discriminates against a class of people without other reasons.”

The ruling went on to say that “it is clear that Kentucky’s laws treat gay and lesbian persons differently in a way that demeans them.”

He also noted the US Supreme Court’s strike-down of the Defense of Marriage Act (DOMA), in saying that a 2004 constitutional amendment specifically defining marriage as between one man and one woman would be struck down.

This does not mean, however, that same-sex marriage is legal in the state of Kentucky.

While noting that there is no requirement for opposite-sex couples to procreate in order to marry, Judge Heyburn wrote: “No one has offered any evidence that same-sex marriages will harm opposite-sex marriages.”

The Attorney General in the US state of Kentucky last year defended the state’s equal marriage ban, despite his office admitting that overturning it would grant equal legal protections to same-sex couples.