Cristiano Ronaldo
Cristiano Ronaldo with girlfriend Georgina Rodriguez and son Cristiano JrGetty

Cristiano Ronaldo has once again been criticised for having children via surrogacy after reports emerged that his one-month-old twins Eva and Mateo were conceived in a US laboratory in June.

The Real Madrid star has been slammed by Gentil Martins, a Portuguese pioneer in the separation of Siamese twins, for using a surrogate mother.

The footballer seems to prefer the surrogacy route, with his son Cristiano Ronaldo Junior also born via the same procedure in 2010.

The veteran surgeon said that he considers "it a serious crime" for an unmarried man to have children using a surrogate mother and added that Ronaldo can no longer be deemed as a role model.

"It's degrading and sad," the surgeon, who still works at the age of 87, told Portuguese newspaper Expresso. "Ronaldo is an excellent athlete, he has tremendous merit but it's moral stupor. He cannot be an example."

Martins also blamed the footballer's mother, Dolores Aveiro, for failing to educate her son.

"Everyone has the right to a mother. I think one of the main people to blame for this situation is Cristiano's mum."

Ronaldo was recently slammed by former Miss Universe, Alicia Machado, for having children via surrogacy, with the Venezuelan-American actor saying that it was against her "religious beliefs" to bring children into the world via a surrogate.

"I do not agree, I don't believe in it. That goes against my religious beliefs," Machado told People magazine. "I agree with that kind of experimenting only when there is a need [like] a mom who maybe has a sister that lends her body.

"What I disagree with is that it has become a trend among many celebrities. Those who have the money go and order children, and I don't agree with that," she added.

Blessed

A post shared by Cristiano Ronaldo (@cristiano) on