Several prominent journalists and activists in Mexico have filed a complaint accusing the government of spying on them by hacking their phones.
The accusation follows a report in the New York Times that says they were targeted with spyware meant to be used against criminals and terrorists.
The newspaper says messages examined by forensic analysts show the software was used against government critics.
Mexican government officials have denied the allegations.
The report says that the software, known as Pegasus, was sold to Mexican federal agencies by Israeli company NSO Group on the condition that it only be used to investigate criminals and terrorists.
The software can infiltrate smartphones and monitor calls, texts and other communications, the New York Times said. It can also activate a phone's microphone or camera, effectively turning the device into a personal bug.
But instead of being used to track suspected criminals, the targets allegedly included investigative journalists, anti-corruption activists and even lawyers who were looking into the disappearance and suspected massacre of 43 students in 2014.
Nine people have now filed a criminal complaint. At a news conference in Mexico City, journalist Carmen Aristegui accused the state of criminal activity.
"The agents of the Mexican state, far from doing what they should be doing legally, have used our resources, our taxes, our money to commit serious crimes," she said.
In 2014 Ms Aristegui helped expose a scandal involving the wife of President Enrique Pena Nieto acquiring a $7m house from a government contractor.
A statement from Mr Pena Nieto's office said that there was no proof that the Mexican government had carried out the spying described in the New York Times.
"We condemn any attempt to violate the right to privacy of any person," spokesman Daniel Millan said.