Mel B's children are word perfect at reciting the expletive-laden Chicago script, after helping their mother perfect her American accent for the musical.

The 41-year-old singer is currently playing Roxie Hart in the show at the Ambassador Theatre in New York, with her run ending on 19 February (17).

Starring in the production is something Mel is thoroughly enjoying, although she admits her American accent leaves a lot to be desired.

However, her youngest children, nine-year-old Angel and five-year-old Madison, are currently with their mother in New York, and have been doing their best to help the Spice Girls star nail the U.S. accent.

When chat show host Stephen Colbert asked Mel if her girls had seen the show, she replied: "Have they seen the show? They are breathing and living the show, because I’m from England so I don’t have an American accent but my kids have helped me rehearse my lines because they have great American accents. And trying to get me to sound like them, even though the text isn’t very kid-friendly, some of it - but yeah, they know the show inside out."

Asked by Stephen what kind of lines she lets her children read, Mel admitted: "Just stuff like, ‘Screw you, you son of a b***h’, but in the context of the show. They were helping me with me Rs because my Rs are really bad because I don’t do an American accent very well… yet."

However, it's not a case of what happens at rehearsal, stays at rehearsal, as Madison has become quite a fan of one particular scene in the show.

In fact, she is so familiar with the scene that she even recites the lines at dinner - much to Mel's concern.

"There’s a scene when these six ladies are explaining how they killed their spouses, and there’s one particular scene that my five year old can just say word for word, about the guy popping the gun and he ran into her knife 10 times, and it wasn’t her fault. So yeah, she does recite that at dinner and I’m like, ‘Oh God, I hope nobody is hearing this!’ " Mel laughed.