The tumultuous relationship between President Jair Bolsonaro and the media heated after the far-right leader criticised a journalist who has written damaging pieces about the first family for one of Brazil's largest newspapers.

Bolsonaro sent a misleading tweet Sunday night saying Constanca Rezende of the newspaper O Estado de S. Paulo had been recorded saying she wanted to ruin the life of Bolsonaro's son, Flavio, and impeach the president.

Rezende has reported on a case of alleged corruption that has cast a shadow over the initial months of the administration.

The case involves alleged irregular payments to Flavio Bolsonaro, a senator who is Bolsonaro's eldest son, as well as to Bolsonaro's wife, Michelle Bolsonaro.

Flavio and Jair Bolsonaro deny any wrongdoing and say they are being politically persecuted.

In the tweet, Brazil's president also said journalists like Rezende wanted "to topple the government with blackmail, disinformation and leaks".

Brazil's Bar Association, the investigative journalism association Abraji and many others condemned Bolsonaro's tweet.

Bolsonaro's comment "shows not only a lack of commitment to the facts, but also more seriously the use of his position of power to try to intimidate media outlets and journalists", the Bar Association said in a statement.

In the audio mentioned by the president, Rezende tells a man who claimed to be a university student researching a paper, "This case can put in a bind and ruin Bolsonaro."

She also said she believes the case could lead to impeachment, an opinion many legal experts agree with. In 2016, then President Dilma Rousseff was removed from office for illegally managing the federal budget.

In one part of the audio, Rezende, speaking in English, expressed concern that nothing would come of the investigation, a common fate of many probes in Latin America's largest nation.

Joao Caminoto, director of journalism at Estado de S.Paulo, told The Associated Press that his main concern after Bolsonaro's tweet was for Rezende's safety.

"She had her social media accounts suspended, her cellphone number was published," Caminoto said. "This is very worrying and it isn't happening only to us. There are frequent attacks on the press and attempts to discredit journalists. It is very well organised."