Brazil’s Supreme Court has been asked by Attorney General Rodrigo Janot to authorize the start of corruption investigations against prominent opposition leader Aecio Neves.

Senator Aecio Neves, who narrowly lost the 2014 election to President Dilma Rousseff, was previously included in a list of some 50 politicians thought to have taken bribes originating from state-run companies, including electricity company Furnas.

The case is linked to the huge corruption scandal that has rocked Brazilian politics over the past year.

Aecio Neves denies any wrongdoing.

If the Supreme Court agrees to open an investigation, the senator will be called to testify within 90 days, Folha de Sao Paulo newspaper reported.

The case is based on allegations made by Senator Delcidio Amaral as part of a plea bargain.

A former leader of the Workers’ Party in the Senate, Delcidio Amaral was arrested in November.

Senator Delcidio Amaral had been secretly recorded allegedly discussing plans to help a detained official flee Brazil in return for not implicating him in a major corruption scandal at Petrobras.

He was released in February after he agreed to testify against other suspects.

Delcidio Amaral said that Aecio Neves had received bribes from officials at Furnas.

He said the scheme was similar to that operated at Petrobras: Brazil’s top construction companies paid bribes to politicians, political parties and senior executives at the company in order to secure lucrative overpriced contracts.

Aecio Neves’s office rejected the allegations, with an aide telling reporters: “References to Senator Aecio’s name are all based on hearsay. There is no proof or evidence of any irregularity.

“These are old questions that have already been the subject of previous investigations, which were thrown out, or questions that have no relation to the senator.”

Rodrigo Janot has also requested the opening of a corruption probe against other senior politicians and officials, the Speaker of the lower house of Congress, Eduardo Cunha, and President Dilma Rousseff’s press secretary Edinho Silva.