FILE - In this Jan 19, 2018 file photo, Guatemalan Attorney General Thelma Aldana, who sent a president to prison and broke up a number of high-level corruption rings, listens to a question during an interview at her office in Guatemala City. On Friday, March 8, 2019, two days after becoming a presidential candidate, Aldana is being accused by the Attorney General's office in a case of irregular hiring practices, (AP Photo/Moises Castillo, File)
camera (The Associated Press) FILE - In this Jan 19, 2018 file photo, Guatemalan Attorney General Thelma Aldana, who sent a president to prison and broke up a number of high-level corruption rings, listens to a question during an interview at her office in Guatemala City. On Friday, March 8, 2019, two days after becoming a presidential candidate, Aldana is being accused by the Attorney General's office in a case of irregular hiring practices, (AP Photo/Moises Castillo, File)

Prosecutors in Guatemala say they have opened a corruption investigation into a former chief prosecutor who is soon to be named a candidate in the June 16 presidential elections.

The Seed Movement party is planning to name Thelma Aldana as its candidate this weekend. Polls show Aldana would probably run second in the race.

Prosecution spokeswoman Julia Barrera would not say Friday what charges the investigation involves, but said it was related to a case of irregular hiring of personnel.

If Aldana is arrested or charged, it could effectively prevent her from running.

The 63-year-old Aldana was Guatemala's top prosecutor from 2014 to 2018. Her biggest successes were the jailing of former President Otto Perez Molina and most of his Cabinet on corruption charges. Perez Molina resigned in 2015.