A lawsuit challenging the US state of Lousiana’s ban on recognising out-of-state same-sex marriage has been announced by a gay rights organisation.

The Forum for Equality Louisiana on Wednesday announced the lawsuit.

It will be filed on behalf of four gay, married couples, and heavily criticises the ban on the recognition of out-of-state same-sex marriages, attacking it for various reasons.

The draft lawsuit claims that revenue department policy, as based on the ban, forces married same-sex couples to falsely claim that they are single on state tax return forms.

It also attacks the state for refusing to recognise both members of a same-sex marriages as the legal parents of a child born to them or adopted.

The Louisiana constitution was in 2004 altered to state that marriage would only “consist of the union of one man and one woman.”

It specifically bans officials from recognising same-sex marriages.

The lawsuit will point to the strike-down of the Defense of Marriage Act (DOMA), and the US Constitution.