Curiosity is fundamental to right to know and we cannot curtail it, the Supreme Court said on Tuesday.

"We cannot curtail free choice of researcher as right to know is a  fundamental right. This will be dangerous," a three-judge bench presided by Justice Dipak Misra said.

The bench was hearing a PIL by Sabu Mathews George seeking direction to ban advertisements relating to sex determination test on search engines.

"There should be no advertisement on sex determination. If somebody does it, it is an offence. But suppose we pass any general order (banning all info relating to sex determination on web), it would offend Article 19(1)(a). It has got its own pedestal and sanctity and we don't think anybody should derail it," the bench said.

Senior advocates Harish Salve and A M Singhvi, appearing for search engines, claimed they don't allow any advertisement on sex determination but they cannot bar all information relating to it due to its importance to people for research and other purposes.

Attorney General Mukul Rohatgi presented the distinction between right to know and advertisement must be recognised.

Advocate Sanjay Parikh, appearing for the petitioner submitted that it has to be considered if search engine is inert or played any active role.

However, the bench said, "the falling of sex ratio has been deprecated earlier...but the question is are we trying to encroach upon the right to know and right of choice".

The court indicated that it may dispose of the matter on April 13.