The show cause notice was issued to Khan yesterday by Supreme Court Bar Association at the Peshawar High Court. Khan lives and works in the northwestern city of Peshawar.
He has said that he performed voluntary service at gurdwaras, including cleaning shoes, during a recent visit to India as "penance for crimes committed by the Taliban".
SCBA president Yasin Azad was quoted by The Express Tribune as saying that Khan had "defamed" Pakistan by polishing shoes outside places of worship in India.
"Although it was the government's duty to issue him the show cause notice, as he is a serving Deputy Attorney General, we have issued it instead," Azad said.
"Khurshid told us that he did this to be pardoned for all the sins he has committed in his life," Azad said.
He contended Khan could have acted in a "more respectable way".
Khan said he was yet to receive the notice and that he was prepared to reply to it. Since he is a Deputy Attorney General, the Attorney General should have issued such a notice, he said. He questioned the basis on which the notice was issued.
"Have I been charged for violating an Indian law? There was no code of conduct we were told to follow."
Khan noted that he was declared a state guest by the Chief Minister of India's Punjab state and that his mission was to convey a better image of Pakistanis in general and Pashtuns in particular.
"What is constituted as defaming the country