Thousands of smartphone users in India woke up puzzled on Friday with a Unique Identification Authority of India (UIDAI) toll-free helpline number saved in their phonebooks by default.

A French security expert, Elliot Alderson, asked UIDAI on Twitter: “Many people, with different providers, 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 without their knowledge. Can you explain why?”

Twitter was abuzz again with the new development after a huge uproar due to Telecom Regulatory Authority of India (TRAI) Chairman R.S. Sharma’s open Aadhaar challenge to critics and hackers.

The UIDAI, meanwhile, has sought to keep its distance from the issue. In a statement released on Friday, it said the toll free number 1800-300-1947 is "invalid."

"The UIDAI has not asked or communicated to any manufacturer or service provider for providing any such facility whatsoever," the statement read.

"The said 18003001947 is not a valid UIDAI Toll free number and some vested interest are trying to create unwarranted confusion in the public. UIDAI’s valid Toll free number is 1947 which is functional for more than the last two years," it added.

The major telecom operators have not released a statement on the issue yet.