Election officials in Colombia have voted to launch an investigation into President Gustavo Petro’s spending during his historic 2022 campaign.

On Tuesday, the majority of the 10-member National Electoral Council (CNE) approved the investigation into Petro and his campaign manager Ricardo Roa.

The probe relates to alleged violations of campaign finance limits by Petro and Roa, who currently serves as the chief executive of Colombia’s majority state-owned energy company, Ecopetrol.

Petro, who became Colombia’s first leftist president following his 2022 election victory, quickly dismissed the investigation as an attempt to unseat him.

“The coup has begun,” Petro said on social media platform X.

The outcome of the investigation could result in fines, but the impeachment of Petro remains a distant prospect.

If the investigation moves ahead, Petro’s case would be heard by the accusation committee of the lower house of Congress. That is where presidents must be tried, according to Colombia’s constitution.

Petro’s coalition has a majority on that committee. No president in Colombia has been removed from office by Congress in at least 30 years.

Tuesday’s announcement comes after two members of the electoral council presented a report in May alleging that Petro’s presidential campaign exceeded financial limits by about $1.2m. Petro has denied the accusations.

In a statement on Tuesday, the council listed 12 financial transactions that authorities allege the campaign did not disclose.

The statement also accused Petro’s campaign of receiving funds from “prohibited sources of financing”, including labour organisations.

Suspicions surrounding Petro’s campaign have grown over the last year. In July, his eldest son, Nicolas Petro, was arrested. He later admitted to prosecutors that he received money from a drug trafficker and used it for his father’s campaign events on Colombia’s Caribbean coast.

Nicolas Petro insisted that his father did not know about the money, though.

The Colombian leader, who has struggled to enact the sweeping social reforms he promised on the campaign trail, has also been enmeshed in other scandals.

This past May, for instance, former members of his government agreed to cooperate with prosecutors as they looked into an alleged bribery scheme related to the purchase of water tankers.