Section 14-136. Rewards

a.  To  members  of  force.  The commissioner for
  meritorious and extraordinary services rendered by  any  member  of  the
  force  in due discharge of his or her duty, may permit any member of the
  force to retain for his or her own benefit any  reward  or  present,  or
  some  part  thereof, tendered him or her therefor; and it shall be cause
  for removal from the force for any member thereof to  receive  any  such
  reward  or  present  without  notice  thereof  to the commissioner. Upon
  receiving such notice, the commissioner may either order the said member
  to retain the same, or shall dispose of it for the benefit of the police
  pension fund.
    b. To informers.  The  commissioner  shall  have  authority  to  offer
  rewards to induce any person to give information which shall lead to the
  detection,  arrest  and  conviction of persons guilty of a felony and to
  pay such awards to such persons who shall give such information. Such  a
  reward  shall  be  offered  only if there be an unexpended appropriation
  therefor. The city shall  make  the  necessary  appropriation  for  such
  purpose.