Within hours of tweeting his Aadhaar number, Elliot Anderson replied to RS Sharma.

Alleged personal details of India telecom watchdog chief RS Sharma were leaked on Saturday after the TRAI chairman threw a challenge and tweeted his 12-digit Aadhaar asking if it had made him vulnerable to any security risk.

A French security expert, who goes by the nickname Elliot Alderson and uses Twitter handle @fs0c131y, in a series of tweets caused ripples on the social media, leaking "personal address, DoB, your alternate phone number" and explaining to Mr Sharma, the Telecom Regulatory Authority of India (TRAI) chairman, how risky it was to make the Aadhaar number public.

"People managed to get your personal address, DoB and your alternate phone number. I stop here, I hope you will understand why make your Aadhaar number public is not a good idea," Elliot Alderson wrote.

R S Sharma, a known defender of Aadhaar, has been maintaining that the unique ID does not violate privacy and the government reserved a right to create such a database of residents since it gives subsidies on state-run welfare schemes.

Amid a debate on privacy concerns, which has also reached the Supreme Court, activists and people in general fear that the 12-digit biometric number was harmful to citizen's privacy.

"My Aadhaar number is 7*************. Now I give this challenge to you: Show me one concrete example where you can do any harm to me," tweeted R S Sharma, whose tenure ends on August 9.

A twitter user had earlier asked R S Sharma to "walk your talk" after the TRAI chief tweeted his interview with an online portal in which he strongly defended Aadhaar and rejected apprehensions that one billion Aadhaar accounts were vulnerable.

He said there had not been a single instance of data being breached and had there been one, the entire Aadhaar database would have been vulnerable.

Within hours of tweeting his Aadhaar number, Elliot Anderson replied to Mr Sharma.

The security researcher posted a picture of RS Sharma with a portion of it blackened. Elliot Anderson, who is known to have revealed security loopholes in the Aadhaar data system, also posted screenshots of Mr Sharma's leaked details with key areas blackened and hidden.

One of the screenshots even carried his PAN details. But that was also hidden.