Brazil's Supreme Court named a new point man to oversee the giant Car Wash corruption probe, which is about to grow thanks to a flood of plea bargains.

At the top of Justice Edson Fachin's workload will be dealing with plea bargains by executives from Odebrecht, a construction giant at the heart of a pay-to-play scheme.

Although their testimony remains sealed, media leaks indicate it will be explosive -- not least by reportedly implicating President Michel Temer.

Here's what we know so far about Car Wash and the looming Odebrecht testimony:

- The scheme -

During much of the 2003-2010 presidency of Luiz Inacio Lula da Silva, corrupt executives at the national oil company Petrobras colluded with contractors like Odebrecht to hand out inflated contracts in return for bribes. The money lined the pockets of important political leaders and also poured into party slush funds.

Petrobras, one of the biggest companies in Latin America, was badly damaged. It has blamed losses of some $2 billion on the scandal.

The damage to public confidence in the political system was just as great. Among those charged with taking bribes is Lula himself. He denies wrongdoing.

Hard-charging prosecutors and judges on the case, meanwhile, have become folk heroes.

- Odebrecht's role -

Odebrecht is a massive Brazilian company involved in major infrastructure projects worldwide.

Led by its former CEO Marcelo Odebrecht, it became a central player in the corruption scheme, paying off so many politicians and Petrobras executives that it ran a special department to organize the graft.

Bribes were given not only to secure sweetheart deals but also to influence political parties and get favorable legislative action.

In a not too successful attempt to boost secrecy, politicians were given codenames such as Babel, Polo and Ferrari.

Odebrecht's former vice president for institutional relations, Claudio Melo Filho, told prosecutors in his plea bargain that some $4.2 million were funneled into the coffers of Temer's center-right party, PMDB, in 2014 alone, according to Brazilian media leaks.

Marcelo Odebrecht was arrested in June 2015 and sentenced to more than 19 years behind bars.

- The plea bargains -

From the start, Car Wash prosecutors have made big use of plea bargains -- offering suspects a chance for lighter sentences if they spill the beans and testify for the government.

The motherlode of plea bargains comes from Odebrecht, not just Marcelo himself but a total of 77 executives.

Their testimony has been filed with the Supreme Court, which hears all cases involving sitting politicians. Fachin will manage those cases, including exercising authority over future evidence-gathering such as wiretaps -- another frequently used Car Wash tool.

Top Car Wash prosecutor Deltan Dallagnol told AFP last month that the number of suspects would double with the Odebrecht testimony.

"We are investigating thousands of multimillion-dollar crimes committed by hundreds of people," he said.

Until now, the highest-profile political players in the scheme have been from Lula's Workers' Party. However, leaks indicate that the Odebrecht testimony will also point the finger at Temer's PMDB -- and the president himself.

"The company's goal was to maintain a regular relationship of financial concessions and requests for help from these politicians... to favor the interests of the business but not necessarily those of the republic," Melo Filho reportedly told prosecutors.