Brave and Bold #70 (1967)

aka. Mr. and Mrs. Hawkman, also known as the Collector, and forced to reveal that the man under the Batman mask is Carter Hall, and realizes his identity has been compromised. He heads to the hotel room of Mr. and Mrs. Carter Hall, and steals Bruce Wayne's X-Ray from his doctor. Comparing the two, and that the man under the Hawkman mask is Bruce Wayne. Still unsatisfied with Balthazar getting that close to their true identities, and uses it to confirm that Batman will return to Wayne Manor after a night of crime fighting. Once there, Balthazar T. Balthazar, Batman finds the tracking device, but he decides to be sure. He takes a secret X-Ray of Batman, convinced that he knows the extremely valuable secret that Batman and Hawkman are actually aliens., he realizes that they must be the same person. Posing as a beggar, he slips Batman a tracking device, intends to collect the secret identities of various superheroes. His computers deduce that Batman is Bruce Wayne, they are drugged with truth serum, they convince Balthazar that it is really Carter Hall that is Batman. While in each others costumes, they set up another opportunity to be captured, this time wearing alien masks under their regular masks. Balthazar goes to jail happy, to pass along the tracking device and set up a sting. By passing along the tracking device