### Clue: Officer returned cut diamonds to firm after scam (6,9)
### Answer: POLICE CONSTABLE 
 ### Explanation: Definition: Officer
 **Reversal of**(returned) LOP(to cut off from the main part of the body) + ICE(a slang for "diamonds") **plus**(to) [ STABLE(firm;steady) **placed after**(after, in an across clue) CON(a scam) ].