Washington, December 10 : Guy Ritchie, who was granted a "quickie" divorce with ex-wife Madonna in November, is scared that the singer may break their custody agreement and keep their kids with her in the US, according to the director's father.

The `RocknRolla' filmmaker was said to have been granted to share custody of the couple's sons Rocco, aged eight, and adopted David Banda, aged three while the kids split their time between New York and London.

The Queen of Pop's Lourdes, her 12-year-old daughter from a former relationship with a fitness trainer, had to reportedly live with her mum in the US.

The kids are presently said to be with Madonna, who is trotting the globe for her `Sticky and Sweet" tour, while Guy is working on his Sherlock Holmes flick in UK.

Guy's father, John Ritchie confessed that his son was troubled that his former wife may keep their kids away from him.

"The children are with Madonna at the moment. Our worry is that she won''t send them back and Guy hopes she won''t keep them," Contactmusic quoted him as telling British magazine Closer. (ANI)