Peruvian prosecutors said late Tuesday they were investigating President Dina Boluarte and her ousted predecessor Pedro Castillo for alleged money-laundering and illegal campaign financing during the 2021 presidential election.
The probe is an expansion of an investigation against the pair over allegations of illegal financing.
Boluarte, Castillo and his former adviser Henry Shimabukuro were being investigated for "the crimes of prohibited financing of political organisations, money-laundering and criminal organisation," the public prosecutor's office said on Twitter.
"The alleged commission of these crimes would have occurred during the electoral campaign of [the left-wing party] Free Peru in 2021," when Castillo was running for the presidency and Boluarte for the vice-presidency, it said.
The prosecutor in the case, Richard Rojas, made the decision after Shimabukuro declared he had evidence Boluarte was aware of alleged irregularities in the collection of campaign funds.
Peru has been embroiled in a political crisis since Castillo was ousted and arrested on December 7, charged with rebellion for trying to dissolve Congress and rule by decree.
Boluarte took over as president but has faced calls to resign by protesters also demanding fresh elections.
The prosecutors' announcement comes shortly before congress, controlled by the right but now an ally of Boluarte, will debate on Thursday the admission of a motion to remove the president.
It is unlikely to pass because 52 votes are needed and the parliamentary left that introduced it has 35.
Boluarte is already being investigated over the deaths of anti-government protesters, amid accusations by rights groups that security forces used excessive force against demonstrators demanding her resignation.
Forty-nine civilians and seven members of the security forces have died in the clashes since the protests started in December, according to the ombudsman's office.
Even if Boluarte faces a concrete charge, as president she could not face a court until her mandate ends in 2026.
Boluarte is Peru's sixth president since March 2018 and the first woman to hold the role.
Castillo, who is being investigated for corruption, is serving 36 months in pre-trial detention on charges of rebellion.