Madonna became emotional onstage over her teenage son during the Auckland stop on her worldwide tour for new album "Rebel Heart." The 57-year-old singer was seen crying during the Saturday night show before dedicating a performance of "La Vie En Rose" to her son Rocco Ritchie.

Rocco currently lives with his father Guy Ritchie in London, who is currently involved in custody battles with Madonna. Up until December, Rocco had been travelling with his mother on her tour.

"That is my son, who I mentioned earlier," Madonna told fans at the Auckland show before breaking down in tears. "He is actually 15, and it's true, there is no love stronger than a mother for her son... If I talk about him too much, I might cry."

"I would like to dedicate this song to him. It's a love song for a man, but I know he'll be one, one day. I hope he hears this somewhere and knows how much I miss him," she said before launching into "La Vie En Rose."

Rocco, 15, was recently ruled by a judge to be better off staying in the U.K. with his father, although the judge noting that the "inability of the parents to come up with a solution" was taking a toll on the child. Ritchie and Madonna's custody battle has led to a strained relationship between the two stars, who divorced in 2008.

Much of the contention comes from a disagreement in parenting styles, with a source claiming that Madonna is concerned for her son after he has "been photographed by paparazzi smoking suspicious cigarettes multiple times, has broken his wrist, shaved his head and been without supervision for days at a time."

"Madonna sees the damage that's being done to Rocco, who has so much potential, which by his father's influence is now being wasted and destroyed due to lack of guidance from [Richie]," the source claims. On Ritchie's side, it has been claimed that he sees Madonna's stern parenting style as "counterproductive" and that "[Ritchie] wants Rocco to have the confidence he lacked growing up."

Rocco is the second-eldest of Madonna's children after 19-year-old Lourdes. Madonna also has two adopted children, 10-year-olds David and Mercy.