Beyoncé's father thinks the singer should be ''proud'' twins run in their family.

The 'Formation' singer and her husband Jay-Z welcomed two babies into the world last month and now her dad Mathew Knowles has realised the double pregnancy shouldn't have come as a shock to anyone.

The 65-year-old showbiz patriarch has been researching his ancestry for a new book and his discovered that, like his new grandchildren - who are believed to be named Rumi and Sir - his own great-uncles were twins.

He said in a video posted to social media: ''In the research that was done for [my new] book, I was able to learn about my heritage, my family, and going back to my great, great grandmother. I was also learning that my grandmother, Hester, actually had brothers that were twins, Sidney Moore and Gitney Moore.

''You can see that the twins started in our ancestry, and Beyoncé should be proud of that.''

While Beyoncé and Jay - who also have five-year-old daughter Blue Ivy together - have remained tight-lipped about their new arrivals, it was Mathew who revealed last month they had been born.

Taking to Twitter, Mathew posted a picture of a birthday note which read: ''Happy Birthday to the twins! Love, Granddad.''

And he captioned the snap: ''They're here!#Beyonce #twins #jayz #happybirthday (sic)''

Mathew also posted the same picture on his Instagram account, which featured the same caption.

Meanwhile, it was recently revealed that although the pair are ''totally exhausted'' after welcoming their twins into the world, the 35-year-old singer and her 47-year-old spouse - whose real name is Shawn Carter - have never been happier.

A source said: ''At nights, Beyonce has been overwhelmed with all the work needed caring for two babies. Despite all the help they are receiving, Jay is still pitching it so that Beyonce has total support.

''Neither Beyonce, nor Jay, have been able to enjoy an entire night of sleep since the twins arrived. They are totally exhausted but at the same time have never been happier as a family.

''Jay-Z is on super dad duty as he has been completely hands-on with the new babies, helping with late-night feedings, burping, and also changing diapers.

''But Jay hasn't stopped there, he has also been spending a ton of time with Blue during the day and their relationship has grown since the new babies arrived.

''Jay watched Beyonce do heavy all the heavy lifting when Blue was born so he is doing his best to be more present with the twins.''