Social media major Facebook has alleged that someone at the Telecom Regulatory Authority of India's office blocked email from its websites which people used for sharing their comments on differential pricing issue -- a key issue of net neutrality.

Facebook has launched a public campaign to defend its free Internet platform Free Basics in response to consultation paper floated by the TRAI on regulatory framework for differential pricing for data services.

The social media apprehends that the regulator may ban its Free Basics platform, which allows access to some websites and applications, and hence launched a massive campaign to gather support in its favour.

According to sources, Facebook in a letter to the regulator, has said that despite clear and timely efforts by millions of Indians to send their comments, 'someone with access to designated TRAI email account appears to have blocked receipt of all emails from Facebook to that TRAI account.'

It said that during its query, it was found that 'on December 17 at 5.51.53 GMT, an individual with access to the TRAI email account designated to accept comments took action that blocked Facebook from delivering any additional email to that address'.

Facebook said that the action by person prevented its system from sending further responsive email to TRAI.