SAO PAULO (AP) — Brazil's biggest newspaper is asking federal police investigate threats against a journalist who published a report alleging backers of a presidential candidate were bankrolling a fake news campaign.

It's a sign of the increasingly heated atmosphere ahead of Sunday's election.

The newspaper last week ran a report by Patricia Campos Mello saying that businessmen linked to Jair Bolsonaro had bankrolled the spread of fake news on the WhatsApp messaging service to benefit his candidacy.

Bolsonaro has denied the report, while competitor Fernando Haddad called on the electoral court to investigate.

The Folha de S. Paulo newspaper said Wednesday there were indications that that Bolsonaro's campaign threatening freedom of the press.

The paper says Campos Mello has received numerous threats via WhatsApp and email.