By Maria Carolina Marcello

BRASILIA (Reuters) - Brazil's suspended House speaker, Eduardo Cunha, denied any criminal wrongdoing on Tuesday and said he will not resign, even though he has already been indicted for corruption and faces the risk of imminent arrest.

The Supreme Court indefinitely suspended Cunha last month on charges of obstructing a corruption investigation, just weeks after he orchestrated the approval of impeachment proceedings against President Dilma Rousseff in the lower house of Congress.

Speaking at a news conference on Tuesday, the veteran politician denied he was seeking a plea bargain with prosecutors to obtain leniency.

"I have not committed any crime, so I have nothing to tell," said Cunha, still defiant despite his alleged ties to the sweeping scandal involving Petrobras, Brazil's state-oil company, in which dozens of government officials and lawmakers are suspected of taking bribes and kickbacks.

Cunha is the first sitting lawmaker to be indicted in the two-year-old scandal by the Supreme Court, the only tribunal authorized to try federal lawmakers. It indicted Cunha in March for allegedly receiving $5 million skimmed from Petrobras contracts for two drillships in 2006 and 2007.

A Congressional ethics committee last week recommended stripping Cunha of his seat and banning him from politics for eight years for lying about Swiss bank accounts. The full chamber is expected to expel him in mid-July.

If he loses his seat, Cunha will lose partial immunity and his case will be sent from the Supreme Court to a lower court judge presiding over most of the graft probe, Sergio Moro, who has already indicted his wife for receiving bribe money.

An evangelical Christian with strong support from the religious right in Congress, Cunha has for months fended off the ethics committee hearings through procedural maneuvers.

The disgraced speaker was once close to interim President Michel Temer, who has replaced Rousseff pending her Senate trial for breaking Brazil's budget rules.

Earlier this month, Brazil's top prosecutor asked the Supreme Court to order Cunha's arrest for obstructing justice.

Supreme Court Justice Teori Zavascki, who has denied requests for the arrest of senior members of Temer's PMDB party including the leader of the Senate, has yet to decide on Cunha's possible arrest.

(Writing by Anthony Boadle; Editing by Tom Brown)