In controversial remarks, Ramdev had said he respects the law of the land and the Constitution otherwise he would have "beheaded" lakhs of people for refusing to chant 'Bharat Mata Ki Jai'.
Terming Ramdev as "vaidya", a practitioner of ayurvedic medicine, Khan said he should confine himself to his own business.
"How a person who had fled from Ramlila Ground (in Delhi) by putting on a woman's dress can talk of beheading those raising dissenting voices," Khan, who is in Australia, said in a statement.
He was referring to the police crackdown on Ramdev's rally in Ramlila Ground in June 2011.
Khan alleged that Ramdev is "busy in spoiling the congenial atmosphere in accordance with agenda of BJP and RSS".