Police wrong to stop little nursery rhyme character (4,2,4)

'police' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'wrong to stop little nursery rhyme character' is the wordplay.
I cannot really see how this works, but
'wrong' could be 'sin' (wrong can mean a sin or crime) and 'sin' is found within the answer.
'little' could be 'l' (abbreviation for little) and 'l' is present in the answer.
'character' could be 'y' and 'y' is present in the answer.
This may be the basis of the clue (or it may be nonsense).