When contacted, Indian Cellular Association (ICA) National President Pankaj Mohindroo told PTI that the industry body had "not got any mandate from anyone to put any such number".
The industry body represents mobile phone brands and large and small handset manufacturers.
The appearance of the number on smartphones had caused a social media furore, as users expressed concerns over how the helpline number had snuck into their smartphone contact list. #UIDAI was trending on the micro-blogging site as the Twitterati sought to unravel the mystery, and questioned the "breach of privacy".
On Thursday, a French security expert, who goes under the pseudonym Elliot Alderson and describes himself as the "worst nightmare" of the UIDAI, had tweeted, "Hi @UIDAI, Many people, with different provider, with and without an #Aadhaar card, with and without the mAadhaar app installed, noticed that your phone number is predefined in their contact list by default and so without their knowledge. Can you explain why?" Alderson, in one of his latest tweets, said, "Ask to yourself: What is the interest for Indian phone manufacturers to add the @UIDAI number by default?."