Mexico's government purchased about $80 million worth of spyware from NSO Group.
Activists, human-rights lawyers and journalists in Mexico filed a criminal complaint on Monday following a report that their smartphones had been infected with spying software sold to the government to fight criminals and terrorists.
The complaint to the attorney general's office by nine people followed a report by the New York Times that some of them had been spied on with software known as Pegasus, which Israeli company NSO Group sold to Mexico's government.
Citing a report by a research group that investigated the alleged spying, the complaint says the attorney general's office and the defense ministry were among government organizations that purchased the software.
Those claiming to be targeted by the software included Carmen Aristegui, a journalist who in 2014 helped reveal that President Enrique Pena Nieto's wife had acquired a house from a major government contractor, as well as Carlos Loret de Mola, a journalist at leading television network Televisa.
Others included in the complaint were anti-corruption activists and lawyers representing the families of 43 trainee teachers whose disappearance and apparent massacre in 2014 created a huge public relations headache for Pena Nieto.
Daniel Millan, a spokesman for Pena Nieto's office, issued a statement saying that there was no proof the Mexican government was responsible for the spying described in the New York Times story. "We condemn any attempt to violate the right to privacy of any person," the statement said.
A Reuters report in 2015 showed government surveillance requests were gathering speed in Mexico, raising concerns about a lack of oversight in a country plagued by corruption and collusion between security forces and criminal gangs.
Mexico's government purchased about $80 million worth of spyware from NSO Group on condition it would only be used to investigate criminals and terrorists, the Times said.