The Brazilian ministry said it could launch an official investigation if Google did not provide a satisfactory response within 10 days, according to a statement released on Thursday.
Google had no immediate comment on the subject, according to a press officer in Brazil.
France's data protection watchdog is already conducting a Europe-wide investigation into the company's use of personal data, which it said was breaking the laws of the European Union.
The company also said it would pool data it collects on individual users across its services, allowing it to better tailor search results and improve service. Users cannot opt out of the new policy if they want to keep using Google's services.
Brazil's Justice Ministry said its questions for the Internet company focused on how the public was consulted during the drafting of the new policy and what kind of authorisation was required from individual users for its implementation.
The ministry's Department of Consumer Defence and Protection also questioned how Google was using the content of private emails to customise its advertising.
The ministry's concerns come as many in Brazil's burgeoning middle class have bought their first computers and taken to the Internet in droves over the past decade, often specifically seeking out Google services such as the social network Orkut.
Nine out of every 10 Internet searches in Brazil are conducted through Google, according to data from local credit research company Serasa Experian.
This is not the first time that Google has been in the legal spotlight in Brazil, where it opened an office in 2005.
Over the years, the company has faced repeated requests from Brazilian authorities to reveal the identity of bloggers and Orkut users who posted information and language violating local libel and anti-racism laws.
The inquiry in Brazil also follows legal complaints filed last year by rivals accusing Google of unfairly favouring product listings from its own shopping comparison service in Internet search results. - Reuters