Miguel Herrera speaks during a press conference after his arrival in Mexico on June 20, 2015, in Mexico city (AFP Photo/Maria Calls)

Mexico City (AFP) - Mexico's former football manager Miguel Herrera, who was fired this week after allegedly punching a reporter, is under investigation over whether he broke election laws by tweeting his support for a party.

Prosecutors are seeking to question Herrera over his tweets in favor of the Green Party during the June 7 midterm election, an official in the attorney general's office told AFP on Friday.

Agents went to his home in the northern city of Monterrey on Thursday to deliver a summons to appear before prosecutors "for the probable commission of an electoral crime," but he was not there, the official said.

The agents "will return next week to deliver the summons to appear," the source said.

Herrera, nicknamed "Piojo" (Louse), has come under fire in recent weeks for his actions on and off the field.

During the election, Herrera and two of his players joined some celebrities in using their Twitter accounts to support the Greens, a controversial party that has been fined $30 million for breaking campaign rules.

Laws forbid any political proselytizing on election day. They could each face $9,000 fines from the football federation, which is also investigating the tweets.

Herrera later came under scrutiny over Mexico's poor showing at the Copa America, the South American tournament, where he took what was considered a B-team because he saved the best players for the Gold Cup, organized by the North, Central and Caribbean (CONCACAF) federation.

While Mexico won its seventh Gold Cup by defeating Jamaica 3-1 on Sunday, it was under controversial circumstances after it was awarded a dubious penalty in a semi-final victory over Panama.

Despite the trophy, Herrera was sacked on Tuesday after a Mexican television journalist claimed that the ex-manager punched him in the neck at the Philadelphia airport in the United States.

Herrera offered a public apology following the incident.