Britain's Duchess Catherine will have six children, a family history website has predicted.

Genes Reunited has guesstimated the Duke and Duchess of Cambridge - who is due to give birth to the couple's first child on July 13 - could be set to have a royal brood if Catherine's family tree is anything to go by.

Head of Genes Reunited, Rhoda Breakell, said: "Following our very close predictions of the birth date, we wanted to look into the Middleton records to see what we might be able to uncover. We were surprised by the number of children in the Middleton family and wonder whether The Duke and Duchess of Cambridge will follow in Kate's ancestor's footsteps.

"Using the 515 million records available on Genes Reunited, people can look back through their family history to discover fascinating patterns which may exist amongst their ancestors."

The site also predicts the couple's second child will be born in April 2016 after looking into the family history of Catherine, who was known as Kate Middleton prior to her nuptials.

Last year, Genes Reunited researchers scoured the royal birth and marriage records from the past 100 years and calculated that 851 days was the average period between a royal wedding and the arrival of a baby.

They predicted that the birth and sex of the Duke and Duchess of Cambridge's first child would be a son born on the 27th August this year. And with the duchess' due date officially confirmed as July 13, their prediction proved strikingly accurate.