Brazil's far-Right election front-runner was accused of setting up a 'criminal network' with big businesses to spread fake news through Whatsapp.

Brazilian media reported that well-heeled supporters of Jair Bolsonaro paid for messaging by third-party agencies, each paying up to 12 million reais ($3.26 million) to spread tens of thousands of attack ads.

Leftist opponent Fernando Haddad, who trails by 18 points, denounced the practice revealed by newspaper Folha de S.Paulo, accusing Mr Bolsonaro of flouting campaign laws by creating "a veritable criminal organisation with businessmen who are using undeclared money to pay for false messages on WhatsApp".

Bolsonaro's campaign did not respond to a request for comment. The candidate's son, Carlos Bolsonaro, accused Folha and Haddad's Workers Party, or PT, of "telling half-truths or decontextualized lies" in a post on Twitter.

Mr Haddad said the PT has witnesses saying Bolsonaro asked business leaders at a dinner in Sao Paulo for funds to pay for the bulk messaging, which he described as undeclared campaign contributions.