Brazilian striker Ronaldo yesterday admitted to being the father of a five-year-old boy born in Japan and living in Singapore, following the result of a DNA test.

“Alex is my son, the brother of three other children. I will always behave as his father,” wrote Ronaldo, 34, on his Twitter social networking account.

“The result of the test confirmed my feelings when I met Alex,” added Ronaldo, who first met the child on Monday.

The DNA test to which Ronaldo submitted confirmed that he was the father of the boy, who was born in Japan and has Brazilian nationality.

The mother of Alex, Michele Umezu, had been trying since 2009 to have Ronaldo recognised as the boy’s father and is demanding child support.

She says she met Ronaldo at a party in Tokyo in 2002 celebrating Brazil’s success at that year’s World Cup in Japan and South Korea.

Ronaldo, she says, returned to Tokyo in 2004 during a tour of Real Madrid, for whom he was then playing. She said she became pregnant by him at that time.

Reports said Michele Umezu was a 28-year-old Brazilian living in Singapore.

Ronaldo, nicknamed ‘Fenomeno’, already has three children: a 10-year-old son with his ex-wife Milene Dominguez, and two younger daughters, one aged 21 months and the other eight months, with his current wife, Bia Anthony.

He rose to prominence as a prolific striker in the mid-1990s, playing for Barcelona, Inter and Real Madrid and winning the World Cup with Brazil in 2002.

He is currently playing for Brazilian side Corinthians but has confirmed that he will retire from the game next year.