GENOT, Rio de Janeiro (AFP) - Brazil has spent the past three weeks immersed in wall-to-wall coverage of a Senate inquiry into why Covid-19 exploded so horribly in the country - a parade of damning, sometimes comical testimony likely to damage President Jair Bolsonaro.

The letters "CPI" - for parliamentary investigative commission - have been splashed across the front pages of Brazil's newspapers almost daily, while news channels carry live broadcasts of the lengthy hours of hearings.

Far from the staid affair its name might suggest, the probe has been flush with insults, arguments, and episodes of general rowdiness, including a senatorial shouting match when one former official was nearly arrested on the spot for perjury.

Brazilians have watched, often dumbfounded, as a succession of current and former officials in the far-right President's administration have struggled to answer senators' questions on how the pandemic has come to claim nearly 450,000 lives in Brazil, second only to the United States.

The discussions revolve mostly around the President and his government's list of unorthodox decisions on Covid-19, which include opposing stay-at-home measures and masks, touting ineffective medications, refusing offers of vaccines, and failing to anticipate oxygen shortages that left patients to suffocate.

Without all that, "how many lives could have been saved?" the commission's deputy chair, opposition Senator Randolfe Rodrigues, has asked repeatedly.

"The government is on the ropes," said political scientist Geraldo Monteiro of Rio de Janeiro State University.

"Every day, new revelations emerge implicating the government. That's putting the squeeze on the administration, and especially Mr Bolsonaro, whose direct responsibility is increasingly clear," he told Agence France-Presse.

"The stream of witnesses testifying on the insanity of the government's behaviour in the crisis has made its irresponsibility clear," leading newspaper Estado de Sao Paulo wrote in an editorial.

The commission, which has a 90-day renewable mandate, will submit a final report to prosecutors that could form the basis of a criminal investigation.

That task lies in the hands of Senator Renan Calheiros, a fiery veteran who has made it clear he will not pull any punches in his report card on the administration's performance.

The prospect has the President's inner circle looking nervous. During one tense hearing, Mr Bolsonaro's son Flavio, also a senator, called Mr Calheiros a "bum".

"He can put on his little show, but he's not going to take me down. Only God can do that," the President, who is not scheduled to testify, said the next day.

The commission does not have the power to launch impeachment proceedings, but the final report could help push Congress in that direction - as a similar probe did in the 1990s, leading to the resignation of then President Fernando Collor de Mello.

Mr Monteiro said such an outcome was unlikely in Mr Bolsonaro's case, given his pragmatic alliance with Lower House Speaker Arthur Lira, the gatekeeper to opening impeachment proceedings.

"It would take a truly explosive revelation," he said.

"We haven't really had any bombs so far - it's more confirming things we already knew."

But the commission stands to embarrass Mr Bolsonaro just as he gears up to run for re-election next year.

His popularity is at an all-time low, and recent polls show him losing to leftist former president Luiz Inacio Lula da Silva if the latter runs.

Opposition lawmakers are not letting the opportunity to attack the administration slip by.

"You owe the country an apology. You're a compass who steered us straight into an iceberg," Senator Katia Abreu told ultra-conservative former foreign minister Ernesto Araujo in one hearing.

The tension is all the greater given that the commission has the power to have witnesses arrested for perjury.

That nearly happened on May 12, when Mr Calheiros called for the immediate arrest of former presidential communications chief Fabio Wajngarten.

The drama lasted long enough for Mr Wajngarten to turn visibly pale, before commission chair Omar Aziz overruled the rapporteur.

The commission has also spawned memes on social media, such as a picture on Wednesday of former health minister Eduardo Pazuello miswearing his face mask in a bunched-up band above his mouth, instantly dubbed the "mask floss" look on Twitter - and condemned by critics as a symbol of the government's Covid-19 response.