Bungling sleuth close to Panther, a con man (7)
I believe the answer is:
hustler
'a con man' is the definition.
(hustle can mean to trick or defraud)
'bungling sleuth close to panther' is the wordplay.
'bungling' indicates an anagram (I've seen this in other clues).
'close to' says to take the final letters (the close/ending of).
The last letter of 'panther' is 'r'.
'sleuth' anagrammed gives 'hustle'.
'hustle'+'r'='HUSTLER'
(Other definitions for hustler that I've seen before include "Swindler" , "Aggressive dealer" , "Conman" , "Prostitute" , "Illicit dealer (mainly US)" .)