Political consultancy Cambridge Analytica's nameplate is seen in central London, Britain, March 21, 2018. REUTERS/Henry Nicholls

BRASILIA: Brazilian prosecutors on Wednesday said they had opened an investigation into whether London-based political consultancy Cambridge Analytica acted illegally in Brazil, as controversy over the firm?s data harvesting practices spreads across the globe.

Prosecutors for Brazil?s Federal District, which includes Brasilia, the capital, said in a written statement they would look into whether the firm, through its partnership with Sao Paulo-based consulting group A Ponte Estratégia Planejamento e Pesquisa LTDA, illegally used the data of millions of Brazilians to create psychographic profiles.

Calls to CA Ponte, as the partnership is called, were not answered.

Prosecutors from a specialised data unit will look into whether there were security breaches that allowed the firm to illegally access personal data.

Regulators and lawmakers in the US and Europe have demanded an explanation of how the consulting firm, which worked on US President Donald Trump?s election campaign, gained access to data on 50 million Facebook Inc users in order to build voter profiles.

Reports on Monday said the firm may have improperly gained access to the data, and Cambridge Analytica has since suspended its chief executive Alexander Nix, while Facebook CEO Mark Zuckerberg admitted that his company made mistakes in its handling of user data.

By many measures, Brazil is Facebook?s third largest market.