Brazil's President Michel Temer is facing charges of corruption and obstruction of justice, according to an investigation released by the supreme court.
Attorney General Rodrigo Janot's charges against Mr Temer threaten to drive him from the presidency.
For the 76-year-old career politician who was not elected, the fall-out could cost him his job. Mr Temer, then vice president, took power a year ago after President Dilma Rousseff was impeached and later removed from office for illegally managing the federal budget.
By Friday afternoon, O Globo, the flagship paper of Brazil's largest media company, was calling for Mr Temer's resignation, delivering a significant blow to his prospects of survival.
The attorney general's formal presentation of evidence is the latest revelation related to a secretly recorded audio that purportedly captured Mr Temer endorsing the paying of hush money to an ex-politician now serving a 15-year prison sentence for corruption.
The audio was first reported by Globo newspaper Wednesday night.
In a plea bargain by the same man who recorded Mr Temer, released as part of the document dump by the Supreme Tribunal Federal, the president is accused of taking 1.5 million dollars (£1.15m) in bribes.
Mr Janot says Mr Temer and Senator Aecio Neves have tried to derail the three-year-old "Car Wash" investigation into a huge kickback scheme at the state-run oil company Petrobras via legislative means and by influencing police investigators.
"In this way, there is evidence of possibly committing the crime of obstructing justice," Mr Janot wrote.
With a formal investigation now opened, Mr Janot's next step will be to decide whether his case is strong enough to send it to the lower Chamber of Deputies in Congress.
If at least two-thirds of the members of the lower house voted in favour, the case would be sent back to the top court, which would then decide whether to put Mr Temer on trial. If the court decided to try him, he would be suspended from office for up to 180 days. A conviction would permanently remove him from office.
At least eight pieces of proposed legislation to impeach Mr Temer have been submitted in Congress, and a stream of people have called for him to step down.
On Friday, former Chief Justice Joaquim Barbosa added his voice.
"There is not another way out: Brazilians must organise, go to the streets and demand with strength the immediate resignation of Michel Temer," tweetedMr Barbosa.
Mr Temer's administration has questioned both the legality and content of the recording.
"President Michel Temer does not believe in the veracity of the declarations" in the recording, according to a statement from his office.
The statement also noted that the person who made the recording, JBS meat-packing company executive Joesley Batista, is under investigation himself and thus was "taking advantage" of the situation. The recording was turned over to prosecutors as part of a Batista plea bargain.
In the documents released Friday, Batista also said his company paid Mr Temer about 1.5 million dollars from 2010 to 2017. Some of those funds were disguised as legal campaign donations and others were channelled to Temer's public image consultant Elsinho Mouco, Batista said.
A Batista's plea bargain, he also told authorities that he transferred 150 million to offshore bank accounts for campaigns of President Luiz Inacio Lula da Silva and his successor in the presidency, Dilma Rousseff.
Ms Rousseff denied the accusations in a statement and said she never had offshore bank accounts. Mr Silva's spokesman said Batista's accusations are hearsay that was never investigated.
For Silva, president between 2003 and 2010, the accusations add to a long list of corruption cases against him, which may ultimately keep him from running for office in 2018.
The sprawling "Car Wash" probe that began three years ago has already put dozens of Brazil's top businessmen and politicians in prison. Many more are being investigated.
After the Globo report on Mr Temer, Brazil's highest court opened an investigation into the accusation late on Thursday and lifted the seal on the nearly 39-minute recording, which is scratchy and often inaudible.