One set of twins. Two different fathers. One very complicated paternity case.

One set of twins, two different daddies.

A mother of twins was fairly surprised to discover her baby girls have two different fathers.

A court-ordered DNA test in a paternity suit filed by a man contesting child support revealed the man was the father of one of the twins, but not the other.

New Jersey Superior Court Judge Sohail Mohammad ruled the babies had been fathered by two different men, a situation he described as rare but not without precedence, America’s ABC News reports.

The mother had named the man as the father of the twin girls, who were born in January 2013, and sought child support.

During the ensuing legal battle, the woman admitted she had slept with two men in the same week and social services ordered a DNA test.

But neither party was expecting these results.

In a ruling handed down this week, Judge Mohammad said it was possible for a woman to have two of her eggs fertilised by two different men if she had sex with both during the same menstrual cycle.

He cited two other US court cases in which this had occurred.

A DNA expert told the court the incidence of twins with different fathers occurred in around one in every 13,000 paternity cases involving twins.

The judge ordered that the man must pay $28 USD per week in child support for his twin.

For more twin craziness, read these stories:

Swapped at birth but only one of the mothers wants to swap the little girls back.

Hold the phone. A baby has been born ‘pregnant’ with twins.

What is this wizardry? Adorable child is incredibly confused by identical twin babies.

One of the Olsen twins just got married. But it’s a secret. SHHH.

Have you ever heard of twins being born to different fathers?