US intelligence leaker Edward Snowden plans to seek political asylum in Brazil in exchange for helping investigate U.S. spying on this country, a newspaper said Tuesday. The former contractor expressed his willingness to aid a Brazilian Senate probe in an "open letter to the Brazilian people" which was published in Folha de Sao Paulo. In the letter, Snowden, who has temporary asylum in Russia, said that until he obtains permanent asylum the U.S. government will continue to interfere with his ability to speak out. Snowden, by downloading a vast trove of classified documents while working as an intelligence contractor for the NSA, has revealed a vast NSA program that culls information from telephone calls and emails around the world, including in Brazil. Snowden avoids directly requesting asylum in the letter, but Folha said his goal is in fact to come to Brazil. It quotes the journalist Glenn Greenwald, who is based in Brazil and has written about many of the documents released by Snowden. Brazil has a long tradition of granting asylum. Snowden praises Brazil's fierce reaction to news it was among the countries the NSA spied on. President Dilma Rousseff canceled a visit to Washington in October after learning of it. Rousseff was among the targets of the U.S. surveillance, via her cell phone, as were the state oil company Petrobras and everyday Brazilian citizens.