Mexico has slammed the US National Security Administration (NSA) over alleged spying on email account of ex-Mexican President Felipe Calderon in 2010, saying such activities are intolerable and breach international law.
Citing NSA's Edward Snowden's documents, German daily Der Spiegel reported that the NSA's "Tailored Access Operations" had gained access to Calderon's email account, and was able to make it a 'lucrative' source of information.
Further, the US agency also attacked a central server in the Mexican presidency network, also used by other members of Calderon's cabinet, and gained information on diplomatic and economic issues.
Mexico's foreign ministry said in a statement that the Mexican government reiterates its categorical condemnation of the violation of privacy of institutional communications and Mexican citizens.
"This practise is unacceptable, illegitimate and contrary to Mexican law and international law," the Ministry said.
"In a relationship between neighbours and partners there is no room for the practises that allegedly took place."
The US agency is also alleged of snooping into e-mails of Brazil President Dilma Rousseff, upon which, the South American nation has set up new rules that mandate internet firms to establish local data storage centres.
Brazil has also decided to develop a secure and encrypted email service, to ban foreign surveillance agencies from intercepting the country's electronic communications.