Footballer Cristiano Ronaldo paid a surrogate mother to have his baby, it was claimed yesterday.

Portuguese newspaper Diario de Noticias said the baby was conceived by the surrogate at the end of last summer in San Diego, where Ronaldo was on holiday.

The boy was born weighing 9lbs 8oz on June 17 while the star was at the World Cup in South Africa.

Diario de Noticias said Ronaldo travelled to the Algarve to meet his son as soon as Portugal were eliminated from the tournament by Spain on June 29.

It gave no further details of the claim.

Ronaldo's sister Katia Aveiro said her brother was 'very happy about becoming a father'.

The youngster is the spitting image of his famous father, with brown eyes and a shock of brown hair, his sister revealed.

Speaking at one of the family's homes in Vilamoura, on the Algarve, Katia told Diario de Noticias: 'He has brown eyes and brown hair like Cristiano.

'He's very happy, of course! Who isn't happy having children? The baby looks like him, although he's still very small to see what his features will be like.

'He's very calm, he just eats and sleeps.'

Katia said her own sons Rodrigo, nine, and four-month-old Dinis 'are very happy' with the new arrival.

She said her brother will reveal his son's name 'when he returns from Madrid', where he is said to be working.

State television channel RTP claimed the boy will be called Ronaldo Junior.

According to reports, the baby was born as the result of a fling with an American woman, who has been paid to stay anonymous.

The footballer became a father two days after playing against the Ivory Coast in the World Cup and four days before he helped Portugal beat North Korea 7-0.

He did not reveal the news to his teammates while in South Africa.