Watch some adorable brow-furrowing as a child sees double when meeting her dad's twin brother for the first time. Courtesy Philochko/YouTube

Identical twin brothers in Brazil have both been ordered to pay child support for a baby after allegedly impersonating each other to trick as many women as possible into sex.

The twins, identified only as Fernando and Fabricio, tried to shirk responsibility for the newborn as DNA tests came back inconclusive, reports The Sun.

The mystifying results are said to have failed to provide a solid answer because the men are so genetically similar.

Each brother tried to blame the other, Brazilian news outlet Globo reports.

But a judge ruled they were denying the innocent child a right to know her biological dad.

District judge Filipe Luis Peruca, at the Cachoeira Alta Court in the central state of Goias, said both brothers must be included on the girl’s birth certificate.

The ruling forces both men to pay maintenance of 30 per cent of the minimum wage — 230 reais ($AU84) a month.

Luckily for the tot this means she will get twice as much as other children from the same economic background.

“It was clear they each used the other’s name, either to attract as many women as possible, or to hide betrayal in their relationship,” the judge concluded.

The mother of the infant told the court she had a brief relationship with the father, who she thought was Fernando.

In her testimony she said she had met the man at a mutual friend’s party.

She said: “He told me he had a twin brother, but I did not get introduced. At the time I did not suspect anything.”

But she later began to question the man’s identity, adding: “The strange thing about the day is that he presented himself as Fernando, but he was with the yellow motorcycle that he said was Fabricio’s.

The judge continued: “One of the brothers, in bad faith, seeks to conceal fatherhood.

“Such behaviour, of course, should not receive a guarantee from the judiciary which, on the contrary, must repress clumsy behaviour, especially in the case in which the defendants seek to benefit from their own clumsiness.

“Given the peculiarities of the case, I believe the decision that most embodies the concept of justice is the one that honours the interests and rights of the child, to the detriment of the tortuous defendants.”

This article originally appeared in The Sun and is republished with permission.