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A Christian official who refused to issue marriage licences to same-sex couples in Kentucky has been ordered to do so by the US Supreme Court.

Rowan County Clerk Kim Davis had argued that her faith prevented her from carrying out her duty.

But the Supreme Court rejected her argument, which means she now has no more legal avenues to pursue.

Her lawyer has said she will pray tonight and decide what to do when her office opens on Tuesday.

Since the court legalised gay marriage nationwide two months ago, Ms Davis has refused to issue any marriage licences to anyone.

The American Civil Liberties Union sued her on behalf of four couples, two gay and two straight.

In making its ruling on Monday, without any comment, the Supreme Court also denied her request for a stay while she pursues an appeal.

If she continues to refuse to issue licences, she could be held in contempt of court, which could lead to a prison sentence.