Luiz Inacio Lula da Silva, Brazil's former president, is likely to face an investigation regarding involvement in an alleged vote-buying scheme.

Local reports on Wednesday said a businessman involved in the alleged scandal says Lula da Silva knew about the corrupt practice and was complicit in the money that exchanged hands.

The vote-buying scheme in congress had led to the conviction of several of the closest aides of Lula da Silva for corruption.

O Estado de S Paulo and Folha de S Paulo newspapers said the government's chief prosecutor, Roberto Gurgel, has recommended that the allegations be heard in court after businessman Marcos Valerio's allegations.

According to Reuters news agency, government sources said that Gurgel had decided not to proceed with the investigation allegations himself instead opting to send the case to a lower federal court instead.

Such courts are able to investigate Lula da Silva as he no longer has immunity from prosecution.

Lula da Silva led Brazil from 2003-10 and is the political mentor to Dilma Rousseff, Brazil's current president.

Rousseff has so far avoided any negative political fallout from the ongoing scandal which has lasted for years.

However, that could change if Lula da Silva is found to have been directly involved.