### Clue: Do Morse? A policeman initially involved with spiv (3,3)
### Answer: TAP OUT 
 ### Explanation: Definition: Do Morse
  A P(first letter,initially of policeman) **contained in**(involved with) TOUT(spiv,eg. a racetrack tout,also a petty criminal)
Defn:  What one needs to do on the telegraph key in order to send out a message in Morse code.  Nice surface, intertwining the fictional Inspector Morse, a cryptic enthusiast, with the criminal element.