Harry Potter actress Scarlett Byrne has announced she has welcomed twins with Playboy founder Hugh Hefner's son Cooper.

The 31-year-old from Hammersmith, London, already has a daughter, 19-month-old Betsy Rose with Hefner. 

Taking to Instagram to announce the news, Byrne said: "My heart grew twice as much this weekend as Cooper and I welcomed our daughters, Marigold Adele Hefner and Blossom Pearl Hefner into the world.

“Our home is full of love with our three daughters and we couldn’t be happier.”

Hefner added in a post on Twitter: “Scarlett and I are overjoyed to share that we welcomed Marigold Adele Hefner and Blossom Pearl Hefner into the world on Saturday, March 26th.

“Today, we are settling back in at home. How blessed we are to be gifted with their life. How lucky we are to be given this love.”

Byrne is known for playing Slytherin student Pansy Parkinson in the Harry Potter films.

She made her debut in the sixth film of the series and reprised the role in the seventh and eighth films.