The Wikileaks website says it has evidence that a number of senior Brazilian government officials were routinely spied on by the National Security Agency in the United States.
It says the NSA was particularly active in economic espionage against Brazil.
Wikileaks published a list of 29 phone numbers of Brazilians in banking, finance and the economy.
According to the website the espionage apparently began in early 2011 or even earlier.
President Dilma Rousseff cancelled a state visit to Washington two years ago when former CIA contractor Edward Snowden revealed that her phones and emails were being spied on.
"The publication proves that not only President Dilma Rousseff was targeted but also her assistant, her secretary, her chief of staff [former Finance Minister Antonio Palocci], her palace office and even the phone in her presidential jet," said WikiLeaks.
"Even on her official travels, President Rousseff is not safe from interception," the group added.
'Things have changed'
Last week, on a visit to the US she declared the spying row was a thing of the past.
"Some things have changed... I believe President Obama," she said during her visit to the US last month when asked about assurances that spying had stopped.
But Wikileaks editor-in-chief, Julian Assange, says American government eavesdropping practices have not been suspended.
"If President Rousseff wants to see more US investment in Brazil on the back of her recent trip as she claims, how can she assure Brazilian companies that their US counterparts will not have an advantage provided by this surveillance, until she can really guarantee the spying has stopped - not just on her, but on all Brazilian issues," he wrote in a statement.
Mr Assange has been given refuge in the Ecuadorean embassy in London since June 2012.
He is fighting extradition to Sweden, where he faces charges of sexual offences against two women.
He denies the charges and say they are political.
Mr Assange fears he will be extradited to the US over the leaking confidential and often highly sensitive diplomatic cables in November 2010.
In late June, Wikileaks published revelations suggesting the US spied French presidents.
The whistle-blowing website says it has obtained more than 250,000 cables passed between the US state department and hundreds of American diplomatic outposts.