Voicing concern over frivolous and vexatious use of RTI Act, Prime Minister Manmohan Singh on Friday said the citizens' right to know should definitely be circumscribed if it encroaches on an individual's privacy.

"There is a fine balance required to be maintained between the right to information and the right to privacy, which stems out of the fundamental right to life and liberty.

The citizens' right to know should definitely be circumscribed if disclosure of information encroaches upon someone's personal privacy. But where to draw the line is a complicated question," he said.

Addressing the seventh Convention of Central Information Commissioners, the Prime Minister said, "There are concerns about frivolous and vexatious use of the Act in demanding information disclosure of which cannot possibly serve any public purpose."

Singh said such queries besides serving little productive purpose are also a drain on the resources of public authorities, diverting precious man-hours that could be put to better use.

"Sometimes information covering a long time-span or a large number of cases is sought in an omnibus manner with the objective of discovering an inconsistency or mistake which can be criticised," he said.

Touching upon the area of public-private partnerships, the Prime Minister said blanket extension of the RTI Act to such bodies may discourage private enterprises to enter in partnership with public sector whereas a blanket exclusion may harm accountability of public officials.