Brazil's National Telecommunications Agency (Anatel) said Monday it has launched an investigation into whether any U.S. firms operating in the country "violated the privacy of personal data and phone calls."

The agency said it would work in conjunction with Brazil's federal police and other federal government bodies to investigate a newspaper report that the U.S. collected billions of telephone and e-mail conversations in the Latin American country.

Any violation is a civil, criminal and administrative offense as "the privacy of personal data and phone calls is a right guaranteed by the Constitution, legislation and Anatel regulations, " the Anatel added.

The move follows revelations published by Brazil's prestigious O Globo newspaper over the weekend that the United States undertakes blanket surveillance of all digital and telephone communications in the Latin American country.

The newspaper said it had access to documents leaked by U.S. intelligence whistleblower Edward Snowden, adding that Washington used social networks and Internet service providers in its mass spying on Brazilian individuals and companies.

It also reported that the United States set up an espionage base in the capital Brasilia in 2002, manned by intelligence agents posing as diplomats. The paper couldn't verify if the operation continues.

Also in the day, Brazil's Communications Minister Paulo Bernardo said President Dilma Rousseff was highly concerned and angered by the revelations.

Bernardo said officials were particularly concerned about possible industrial espionage.

Brazil's Foreign Minister Antonio Patriota said on Sunday the government was "gravely concerned" by the spying allegations and has requested the U.S. government to explain.

Brazil plans to call for better multilateral regulations governing telecommunication security at the International Telecommunications Union based in Geneva, Switzerland, and also plans to submit Internet privacy initiatives at the United Nations, Patriota said.