May 27 (UPI) — Colombian President Gustavo Petro is under criminal investigation over allegations of improper political interference four days before voters head to the polls to elect the country’s next president.

Colombia’s House Investigation and Accusation Commission, a congressional body responsible for investigating sitting presidents, opened the investigation on its own initiative following a series of public statements and social media posts by Petro tied to the presidential election scheduled for May 31.

Colombian law strictly prohibits executive branch officials from intervening in electoral contests or using their office to favor or harm candidates.

The case against Petro is based on several recent incidents that critics say violated the principle of presidential neutrality.

Among the main pieces of evidence are posts on X in which Petro shared photos from campaign rallies held by ruling coalition candidate Iván Cepeda of the leftist Historic Pact coalition in the cities of Barranquilla and Bogotá.

The accusations also include repeated verbal attacks against opposition figures such as conservative Sen. Paloma Valencia and independent lawyer Abelardo de la Espriella, according to Colombian broadcaster NTN24.

News outlet Infobae Colombia reported tensions escalated after presidential candidate Claudia López filed a formal complaint documenting 20 separate actions in which she accused Petro of attacking her through the media while knowingly violating electoral regulations.

Attorney General Gregorio Eljach formally requested a detailed report on the investigation and more than a dozen additional complaints filed against Petro for alleged conduct affecting the balance of the campaign.

Petro has defended himself publicly, arguing his calls to “vote for life or death” reflect support for his ideological positions and government agenda rather than illegal backing of specific candidates. According to Blu Radio, Petro denied that his statements constituted selective or unlawful support.

The controversy erupted during the final stretch of Colombia’s presidential campaign ahead of Sunday’s first-round vote to choose Petro’s successor for the 2026-2030 term.

The race remains deeply polarized, with polls showing a close contest. Cepeda leads voter intention polls with 35.3%, campaigning on continuity for Petro’s leftist political project. Valencia follows with 25.7%, leading a coalition of conservative and centrist sectors. De la Espriella ranks third with 20.4% under a far-right platform.

The atmosphere before the election had already been strained by Petro’s recent statements questioning the transparency of the electoral system. The president called for “massive oversight” by election observers and suggested possible foreign interference in the election.

Colombia’s Defense Ministry has deployed 246,000 security personnel under “Plan Democracia,” a nationwide election security operation intended to protect polling stations. Overseas voting began May 25.

If no candidate secures an outright majority Sunday, Colombia will hold a runoff election June 21 amid an unprecedented judicial investigation into the sitting president.