In the latest instalment of Brazil’s "trial of the century", a top aide to former President Luiz Inacio Lula da Silva (known as Lula) was found guilty of corruption by the Brazilian supreme court last week. The long-awaited verdict relates to a corruption scandal from 2003 to 2005 known as the Mensalao (meaning big monthly allowance), when illegal payments and benefits were used to buy votes in parliament for Lula's ruling party.

It doesn't end there. In total, 37 politicians and business people currently face charges of buying political support for Lula’s government.

Corruption is endemic in Brazil, but this scandal – and the televised court case that has followed – has prompted a glimmer of hope. People are starting (indeed daring) to ask whether this is the beginning of a new era of accountability for the giant Latin American nation. Just a few years ago, bringing down such high-ranking people would have been unthinkable. Is this a moment of change?

A scandal erupts

This week’s ruling was a long time coming: in May 2005 a Brazilian magazine exposed a post office official for accepting large amounts of cash from an undercover reporter posing as a businessman in exchange for a contract. The reporter claimed he had the backing of politician Roberto Jefferson. The politician then came forward to reveal that he’d been paid $2.25m to vote for legislation sponsored by Lula's Workers' party (known as the PT). He claimed his party as a whole had been paid up to four times that amount.

According to prosecutors, a group of a few dozen political figures, executives and business people formed a "criminal organisation" responsible for buying political favours. Politicians from coalition parties allegedly received monthly payments of large sums of money – in cash – in return for their support for the minority government, which was led by the PT.

Jose Dirceu, who was one of the founders of the PT and Lula's chief of staff from 2003 to 2005, was fingered as the mastermind behind the payoffs. Soon after allegations were made public, he resigned and was impeached by Brazil's congress. Lula, however, maintained he knew nothing of the payoff scheme. He was re-elected a year later and was never implicated in the case.

The long-awaited trial begins

In August of this year, prosecutors finally put 37 defendants on trial for their alleged involvement. The defendants have faced charges ranging from corruption and embezzlement to money laundering and misuse of public funds. Last week, Dirceu was the latest of the accused to be convicted of using public funds to "buy" the support of opposition parties. The court has found 20 of the defendants guilty so far, but this case marks the first time the supreme court has convicted a politician for corruption in Brazil.

Dirceu maintains that he is innocent and claims that false allegations were made by competing political parties in an effort to bring down the PT-led government. Others in Brazil have also criticised the court, claiming that it lacks evidence to prove some of the defendants guilty.

The trials are expected to continue for days or even weeks, and while sentences won't be revealed until the very end of all of them, those convicted could face between two and 12 years behind bars. Experts predict that many prominent politicians and business people will actually be sentenced to jail time – a rare occurrence in Brazil.

What does this mean for Brazil?

While the case is clearly historic, some warn that we shouldn't draw conclusions too quickly. The trial is one example among many cases of widespread corruption in Brazil, whose economy loses at least $20bn to corruption each year. And some legal experts have said that expectations for lengthy prison terms for the highest-ranking politicians may be too optimistic.

But the PT's new leader, President Dilma Rousseff, who served as Lula’s chief of staff until 2010, has taken encouraging steps to tackle corruption. Rousseff, whose approval ratings have remained high, has stood back and allowed the trial to run its course. Since taking office in January 2011, she also pushed seven of her cabinet ministers out of their posts following allegations of wrongdoing.

Despite her efforts, the trial may have wider consequences for the PT in local elections currently taking place across the country. During the first round of voting in early October, the PT had its worst showing since 1996 in the race for mayor of Sao Paulo. The second and final round will take place at the end of October.

Whatever the final outcome of all the trials, and the resulting sentences, this case is a key test for the country. Now, for the first time, a whole host of powerful businessmen and politicians are set to be punished for their wrongdoing.

However, the promise of this historic moment will be lost if it does not prompt deeper, more fundamental questions to be asked. High-profile punishments for certain individuals must not allow those in power to claim the problem is solved, when it is not.

There is still so much more work to do. Brazil needs urgent reforms to its political and justice systems, which tackle the underlying culture of corruption. Without that, the "trial of the century" could close, and things could go back to business as usual.

Sources: BBC, International Business Times, Reuters, Chicago Tribune, New York Times, TIME, Guardian