A former congresswoman who proposed to amend the American Constitution to ban same-sex marriage made US news after the New York Times claimed she had signed a brief to the Supreme Court in favour of marriage equality, only for the paper to admit it had misread a list of names.

The claim that Marilyn Musgrove, a former Representative of Colorado, had added her signature to those of 75 other high-profile Republicans who had signed a “friend of the court” brief earlier this week urging the Supreme Court to support same-sex marriage, caused a stir due to her background as an ultra-conservative congresswoman.

The New York Times broke the story earlier on Wednesday, which was quickly picked up by other news sources who were surprised that the woman rated the “most conservative member of Congress” by the American Conservative Union in 2006 had apparently undergone a complete u-turn on her views.

In 2006, Mrs Musgrave was a key sponsor of the failed Federal Marriage Amendment, which aimed to change the US Constitution to include a ban on same-sex marriages.

She was also attributed with the quote: “If we have gay marriage, our religious liberties are gone… this battle is the most important issue that we face today,” made at a summit of the Family Research Council.

The story that Mrs Musgrave had changed her mind and acted in favour of legalising same-sex marriage ran for hours before she denied signing the briefing.

“I’m very befuddled by this story,” she told Fox31. “There’s absolutely no truth to that [New York Times report]. I’m reading it thinking, ‘what in the world?”

“I wasn’t even aware of it. I have not changed my position. I’m trying to imagine where anyone would get that information and I can’t figure it out.”

The New York Times later stated that they had mistakenly run the story that Mrs Musgrave signed the brief because her name was included in the title of her former district director, Betty June Nikkel, who did sign.

“An earlier version of this story incorrectly stated that former Representative Marilyn Musgrave, Republican of Colorado, had signed on to the brief. The brief was signed by her district director, for himself,” said the paper.

The paper said they had apologised to Mrs Musgrave.