He said on his Twitter account: "Alex is my son and the brother of three more beautiful children. He will always have me as a father."

Ronaldo, whose name was occasionally related to sexual scandals over the past years, is already a father of three, one son and two daughters.

According to local reports, Alex's mother is Michele Umezu, a Brazilian model who first met Ronaldo when she was living in Tokyo in 2002.

Ex-Real Madrid hitman Ronaldo, 34, is planning to play one more season with Brazilian outfit Corinthians before retiring.