Madonna breaks down on stage over son Rocco

Madonna has broken down on stage in New Zealand while dedicating a song to her teenage son, who is the centre of custody dispute between the music star and her ex-husband Guy Ritchie.

RELATED: Guy Ritchie 'Determined as Ever' for Son Rocco to Remain in His Custody After Madonna Visits Him in London Ahead of Rescheduled Court Date

The singer was in Auckland on Saturday when she told the audience, "if I talk about him too much, I'm going to cry."

She told fans, "there's no love stronger than a mother for her son" before going to dedicate La Vie en Rose to the 15-year-old.

Madonna. Photo: Getty

Gossip site TMZ reports Rocco has been living with his UK filmmaker father Ritchie in London and that a judge has ruled his parents need to work out an amicable resolution to visitation rights.

The custody battle is alleged to have started in December, when Rocco left his mother's world tour to fly to Britain to stay with his film director father.

Rocco ignored Madonna's pleas - as well as a New York court order - to return to the US, preferring instead to remain in Britain with Ritchie.

Just last week, a new legal bid was launched at the Family Division of London's High Court, a judge urged the couple to settle their differences out of court, reports The Mail On Sunday.

Madonna plays Auckland's Vector Arena on Sunday night before opening her Australian leg of her Rebel Heart tour at Rod Laver Arena in Melbourne on Saturday.