A member of the Indian security apparatus, who has worked with the American security team, says everyone is hugely impressed with the efficient manner in which the dog conducts operations.
The dog has accompanied Obama on every presidential tour.
Khan has been trained for two years in anti-sabotage activities.
The Americans try not to project him too much since he is a special member of their squad and an expert at countering surprise attacks.
Apart from sniffing around and sanitising activities, the German Shepard specialises in counter attacks. He is capable of neutralising three men at one go in the event of an attack, an Indian security source revealed, speaking with some awe.
Sporting a collar 'MWD Khan' this dog has his own passport. Dogs who are part of the security detail usually travel with papers, but an exception was made in Khan's case.
American officials told their Indian counterparts that Khan is the best in the business and this is why he has been chosen to guard the president.
Khan has already visited Mumbai and Delhi twice, checking every location Obama will visit in both cities. On Saturday, Khan was part of the security ring that preceded the president on each of his stopovers in Mumbai.
No information is available about the origin of his name. Some earlier reports suggested that sections of the Muslim community were offended that a dog named Khan was part of President Obama's security team.
Earlier: Obama's security dog named 'Khan': Muslims irked