Football star Cristiano Ronaldo has announced the death of one of the twins carried by his pregnant partner.

Ronaldo and his partner Georgina Rodríguez had revealed last October they were expecting twins but the 37-year-old posted on Instagram the sad news that his son had passed away it appears during childbirth.

The other twin, a baby girl, survived.

"It is with our deepest sadness to have to announce that our baby boy has passed away.

"It is the greatest pain that any parents can feel. Only the birth of our baby girl gives us the strength to live this moment with some hope and happiness.

"We would like to thank the doctors and nurses for all their expert care and support.

"We are all devastated at this loss as we kindly ask for privacy at this very difficult time. Our baby boy, you are our angel. We will always love you.

Ronaldo already is a father of four, Cristiano Jr from a previous relationship and has twins Eva and Mateo via a surrogate.

Rodríguez gave birth to their youngest Alana Martina in 2017.

Ronaldo's sister Katia Aveiro led tributes referencing their father Dinis who died of liver failure in September 2005.

"Our angel is already on father's lap. And our little girl is there firm and strong and full of health and is going to show us with every day that only love matters," she posted.