A constant critic of Aadhaar, American whistle-blower Edward Snowden on Sunday called Aadhaar an "improper gate to services" and suggested that demands to link Aadhaar to bank and telecom services should be criminalised.

While tweeting his comments, Snowden shared an article on Aadhaar written by former chief of the Research and Analysis Wing (RAW), KC Verma.

Snowden has spoken against Aadhaar in the past. Earlier in January, he said the database conceived of by the Indian government could be "misused and abused".

Snowden also spoke out in support of an English daily journalist who did an investigative piece on Aadhaar data being sold for as little as Rs 500. Snowden said the the journalist deserved an award, not an FIR.

Snowden is a former CIA employee famously known for leaking classified information that exposed a massive surveillance operation run by the CIA. He is currently living under asylum in Russia.

While tweeting his comments, Snowden shared an article on Aadhaar written by a former chief of the Research and Analysis Wing (RAW).