National Security Agency whistleblower Edward Snowden has written in "an open letter to the Brazilian people" that he would be willing to help Brazil's government investigate US spying on its soil, but that he could do so only if granted political asylum.In a letter obtained and published early on Tuesday by the Folha de S Paulo newspaper, Snowden said he was impressed by the Brazilian government's strong criticism of the NSA spy programme targeting internet and telecommunications worldwide, including monitoring the mobile phone of the Brazilian president, Dilma Rousseff.Brazilian senators have asked for Snowden's help during hearings about the NSA programme's aggressive targeting of Brazil, an important transit hub for transatlantic fibre-optic cables."I've expressed my willingness to assist where it's appropriate and legal, but, unfortunately, the US government has been working hard to limit my ability to do so," Snowden says in the letter, translated into Portuguese by the newspaper. It did not make the English original available online."Until a country grants me permanent political asylum, the US government will continue to interfere with my ability to speak out," it adds.Early morning calls to Brazil's presidential office and to the foreign ministry were not answered.The Guardian first published accounts of the NSA's spy programmes in June, based on some of the thousands of documents Snowden handed over to the Brazil-based American journalist Glenn Greenwald and his reporting partner Laura Poitras, a US filmmaker.Rousseff cancelled a visit to Washington in October that was to include a state dinner. She has joined Germany in pushing for the United Nations to adopt a symbolic resolution that seeks to extend personal privacy rights to all people.Rousseff has also ordered her government to take measures including laying fibre-optic lines directly to Europe and South American nations in an effort to "divorce" Brazil from the US-centric backbone of the internet that experts say has facilitated NSA spying.The Snowden letter was published a day after a US district judge ruled that the NSA's bulk collection of millions of Americans' telephone records probably violates the US constitution's ban on unreasonable search. The case is likely to go all the way the supreme court for a final decision.(theguardian.com)ANN.Az