Brazil has demanded an explanation from internet giant Google about private wi-fi data allegedly collected while photographing for its Street View maps.
A court told the firm to present a reply by Saturday or face a daily fine of about $45,000 (£28,000) a day - up to a maximum of $450,000.
US and European courts have already fined Google for illegally harvesting data through the Street View programme.
Google says it has removed the data collection facility from the vehicles.
The decision by a court in the capital, Brasilia follows a complaint lodged by the Brazilian Institute of Computer Policy and Rights.
It based the allegation on similar cases in other countries and demanded that Google reveal if it also collected data in Brazil.
The Street View project cars are equipped with cameras and antennas to take 360-degree photos of streets and houses, which are later stitched together and posted as online maps.
Rio de Janeiro, Sao Paulo, Belo Horizonte and other major Brazilian cities have been photographed by Google.
Earlier this year, Google agreed to pay a $7m (£4.3m) fine for collecting people's personal data without authorisation in the US.
In a settlement with 38 US states, the internet giant agreed to destroy emails, passwords, and web histories collected by Street View cars between 2008 and 2010.
Germany also fined the company 145,000 euros (£125,000) for illegally recording information.
The country's data chief called it "one of the biggest known data protection violations in history".