A young child may have dobbed her father in by telling a police officer that he speeds all the time.

An officer stopped a car travelling at 67 kilometres an hour outside a Hamilton school in a 40km/h zone earlier in the week.

The driver had very little comeback, but his pre-school aged daughter sitting in a car seat wound down her window and in a very polite voice, said: 'excuse me Mr Policeman, my daddy always speeds'.

Police say there's no record of what dad said next.