Brazil's Lower House of Congress Speaker Eduardo Cunha will be facing an investigation regarding corruption allegations.

The council's decision to proceed with an investigation was decided last Wednesday.

Cunha has 10 days to present a written defense to the chamber's ethics council after he was officially notified of the probe on Monday. There are claims that Cunha lied to Congress over his use of secret Swiss bank accounts.

Cunha refused to accept the council's notification, saying that he is swamped with meetings.

Cunha Denies Allegations

In a parliamentary inquiry last March, the speaker said that he had no Swiss bank accounts. However, Swiss authorities revealed that Cunha, his wife and his daughter all possess accounts in Switzerland. Cunha argued that the accounts are beneficiary trusts and not personal accounts.

Cunha, a main adversary of President Dilma Rousseff, is also facing corruption, tax evasion and money-laundering charges over bribery accusations. The $5 million in bribes he is accused of taking was part of a huge bribery and embezzlement kickback scheme involving Brazil's national oil company, Petrobras.

Ten Supreme Court judges voted unanimously to indict Cunha over accepting bribes to assist a contract worth $1 billion, which was used to build two oil drilling ships for Petrobras.

Refusal to Step Down

A number of politicians have requested Cunha to step down from his post while the investigation is ongoing, but the speaker wouldn't budge. In December, police raided his homes and seized a computer, cellphone and documents.

Cunha has accused prosecutors of "persecuting him in retaliation for his impeachment drive." But his critics on the left "accused him repeatedly of the opposite: that he was wielding the impeachment weapon as revenge for his own troubles."

Cunha has opened impeachment proceedings against Rousseff in December. The president was outraged by Cunha's move, and hit back by saying that the speaker himself is connected with the Petrobras kickback scheme, also dubbed as Operation Car Wash.

Cunha is part of the PMDB Party, which is currently in a rough alliance with Rousseff's Workers' Party. Cunha's conviction could help Rousseff, who is also in hot water over accusations in electoral court that she mismanaged finances for her 2014 re-election bid.

One of Rousseff's most senior former allies, Workers' Party Senator Delcidio do Amaral, is reportedly gearing up to testify against the president. Do Amaral is also accused of involvement in the Petrobras scandal.

Rousseff is facing widespread blame for the worst ever recession that is currently happening in Brazil.