As Angies List member services said - many, or probably most, plumbers will not work on whirlpool tubs and jacuzzis and such, so may need to go with a Pool and Spa firm if the leak is in the unit itself.
Usually there is an access hatch on the side - turn off breaker and open that and feel around for wetness, tracking from the wetness on the floor/subfloor on up (at least usually upward to find the source unless spraying out of a fitting or cracked pump or such) until you find the source - might just be a loose fitting or weak spring connector on a flex hose or such which you can fix yourself.
