Madonna GuyRitchieKids200.jpg It looks like Madonna and Guy's divorce could get ugly when it comes to where the kids live.

Guy is bringing in the big guns - hiring a top british legal expert to try and keep Madge from moving their 3 kids to the US permanently.

During their eight year marriage, London was the family's home base.

But now, the UK's Daily Mail reports that Ritchie has hired Steven Cobb, CQ, who is considered a specialist in family law cases where the children's country of residence is in dispute.

Madonna and Ritchie have an eight year old son, Rocco, who born in the US. They jointly adopted another son, David, 3, from Malawi in 2006.

Madonna has a 12-year-old daughter, Lourdes, from a previous relationship.

Fiona Shackleton, who's no stranger to high profile splits - she represented Prince Charles and Sir Paul McCartney in their divorces - has been hired as Madonna's attorney.