The Mexican attorney general's office said on Sunday it is investigating the purchase of Pegasus computer spyware by the previous administration and whether it was carried out legally.
In a statement, the office referred to existing probes of two people, including a prominent ex-official, into the use of Pegasus spyware, days after the current government denied it had spied on journalists or critics.
Pegasus belongs to Israeli spyware firm NSO Group, which typically only sells the software to governments or law enforcement organizations.
In the statement, Mexican prosecutors said they were looking at the acquisition of Pegasus by the prior attorney general's office for 457 million pesos ($23 million). They were trying to establish if it had been done with the proper justification, and had followed requisite public tender procedures.