Adding to investigations by Swiss and German prosecutors, HSBC's Swiss private bank must now also face trials in France to answer charges over an alleged tax-dodging scheme for wealthy customers.The French financial prosecutor's office confirmed its intention on Friday, after that Le Monde reported that HSBC had turned down the opportunity of a £1bn fine which would have avoided trial.French prosecutors aim to have the Swiss bank, which has admitted failings in compliance and controls, tried for money laundering related to tax fraud and unlawful soliciting of clients, according to a source cited by Reuters.The lender has been at the centre of a scandal sparked by a former HSBC employee who in February leaked the bank's client data to the media, while its parent company, HSBC Holdings is also under investigation by French authorities.The Swiss banking arm was searched by Swiss prosecutors in February as part of their money-laundering investigation, while later being investigated by German regulators due to alleged tax evasion by its US clients.French authorities believe almost 9,000 customers in total have illegally transferred their money to HSBC's Swiss bank between 2006 and 2007, according to Le Monde.HSBC's Swiss division has until April to respond to French judicial authorities, otherwise the magistrates will have the final word on whether to hold a trial.HSBC shares were down 0.09% to 559.80p at 15:21 on Friday.