SAO PAULO, June 16 (Reuters) - Credit Suisse Group AG said an internal investigation has found no evidence that a former banker, Sérgio Firmeza Machado, used his position at the bank to help his father funnel illicit campaign donations to Brazilian politicians as part of a sweeping corruption scandal.
Firmeza Machado's father Sérgio, a former senior executive at state oil firm Petróleo Brasileiro SA , has told prosecutors he helped raise at least 100 million reais ($29 million) in legal and illegal funding for political parties as head of Transpetro SA, the company's ship leasing and gas transport unit, between 2003 and 2015.
The older Machado avoided jail after signing a plea deal in the so-called "Operation Car Wash" probe, which is investigating political kickbacks, money-laundering and graft at state firms that began in 2003.
The banker and his two brothers also cut similar plea deals, helping shed light on how their father funneled payments to ruling coalition parties and senior politicians.
In excerpts of a plea deal made public by the Supreme Court on Wednesday, Firmeza Machado admitted opening an account at HSBC Holdings Plc's Swiss unit around 2006 to help his brother Expedito receive "donations" from their father that came from bribes paid by Transpetro contractors.
Firmeza Machado also said his brother sought his advice on how to reinvest money that contractors wired to the account. He acknowledged maintaining occasional contact with members of the companies that paid bribes.
However, Firmeza Machado testified that none of the events under investigation were related to his job at Credit Suisse.
Red flags popped up inside Credit Suisse about a year ago when Firmeza Machado, 38, discussed with senior staff the legal situation of his father, according to a source with direct knowledge of the matter who requested anonymity due to the sensitivity of the issue.
After months of checks in which Firmeza Machado's emails, personal investments and activities were analyzed, Credit Suisse staff in Brazil found no sign of wrongdoing, the source added.
In a statement to Reuters on Wednesday, Credit Suisse said it conducts regular compliance checks on all employees. Such checks found no evidence of wrongdoing or any sign of conflict between Firmeza Machado's work and the bank's internal rules.
Efforts to contact media representatives for Firmeza Machado were unsuccessful. Rio de Janeiro-based Tórtima, Tavares & Borges Advogados, the law firm representing Machado and his children, declined to comment beyond the plea deal.
HSBC did not comment on Firmeza Machado's Swiss account.
Sérgio Firmeza Machado, who joined Credit Suisse in 2000 when he was 22, left in April as part of a global restructuring of its fixed-income activities.
After starting as a junior analyst, Firmeza Machado rose through the ranks, joining the fixed-income desk in 2004 and becoming an executive director at Credit Suisse's local unit in 2012.
The banker formed part of a team that helped underwrite dozens of loans to companies bracing for Brazil's initial public offering boom between 2005 and 2008.
Staff at Credit Suisse had full knowledge of Firmeza Machado's ties to his father and the Machados were not Credit Suisse clients, the source said.
In the plea deal made public on Wednesday, his father accused interim President Michel Temer of seeking campaign donations stemming from the kickback scheme at Petrobras, as the state oil company is known, for one of his party's mayoral candidates four years ago.
Temer has adamantly denied the older Machado's accusations.
Temer was vice president until last month, when President Dilma Rousseff was suspended from office to face trial in the Senate on charges of breaking budget laws.
Newspapers leaked part of the older Machado's testimony after the Supreme Court validated it in May. His accusations rocked the incoming Temer administration, forcing the early departure of two cabinet ministers.
($1 = 3.4721 Brazilian reais)
Editing by Daniel Flynn and Tom Brown