Notoriously private couple Enrique Iglesias and Anna Kournikova have shared the first pictures of their newborn twins to the whole world via Instagram.

The Spanish singer, 42, and former tennis player, 36 – who have been together on and off since 2001 – rarely post images from their personal lives, but couldn't deprive their followers a sneak peek of their adorable babies any longer. One of the pictures, showing a doting Iglesias gazing at one of the twins has already notched up over a million likes.

The couple shared individual pictures onto their Instagram accounts on Tuesday (16 January) under the caption "My Sunshine", opting to feature just one baby in each photo.

Russian star Kournikova reportedly gave birth to the twins, a boy named Nicholas and a girl named Lucy, on 16 December at South Miami Hospital.

They managed to keep the pregnancy a secret and out of the public eye until a few weeks before the birth.

Fans have gone wild over the new pictures, with one person commenting on Iglesias' post: "Wow-wow! It's Great Congratulations and many-many blessings for you, Mommy, Daddy & little."

While someone else said: "Congrats, so adorable." A third added: "I reallly love the picture ❤️ you have a beautiful twins god bless him, We love youu Enrique ❤️."

Speaking to Hola! magazine in December, Iglesias' mother Isabel Preysler said of the babies: "Enrique is extraordinarily happy in these moments."

The couple have been dating for the past 16 years after meeting on the set of Iglesias' music video for Escape back in 2002, and broke up in 2013 before reconciling.

My Sunshine

A post shared by 🐾 Anna 🎈Аня (@annakournikova) on

Iglesias was quoted by the Daily Star as having married Kournikova in 2007 before separating, but this has not been confirmed. They also sparked speculation of an engagement last year when Kournikova was spotted wearing a large diamond ring on her wedding finger.

In 2014, Iglesias said: "Well the marriage bug to me, I don't think it would make me any happier. I'm not against it by any means. Yes, kids at some point, I would.

"Hopefully the day that I have kids I can lay back a bit and not travel as much and not be touring as constantly. I don't want to be on the road for six or eight months and then come back and not recognise my own child."

The new parents have since invested in a $20m home to be built on a private island in Miami.

Enrique Iglesias
The couple sparked wedding rumours last year when Kournikova was spotted wearing a large diamond ring on her wedding finger Reuters