A Brazilian presidential candidate is accusing his far-right adversary of electoral fraud for allegedly allowing friendly businessmen to secretly pay to spread slanderous messages.

The accusations by leftist Fernando Haddad follow a report published Thursday by the daily Folha de S.Paulo saying that businessmen linked to Congressman Jair Bolsonaro allegedly bankrolled the spread of fake news on the WhatsApp messaging service.

Haddad said he has leads for Brazil's federal police to follow.

If true, the action could be a violation of campaign finance laws since companies can't give money to candidates.

On Twitter, Bolsonaro rejected the allegations.

Brazil's electoral court has already ordered Bolsonaro's campaign to remove anti-Haddad content it declared as false news.

The two candidates are competing in an Oct. 28 runoff.