Banking giant HSBC has criticised the "excessive" actions of authorities in France after it became the first jurisdiction to place the wider group under formal criminal investigation over the activities of its Swiss private banking arm.
The group said it was ordered to post bail of one billion euro (£720 million).
Its Swiss unit is already under investigation by authorities in France and other countries but this is the first time that the wider group has formally become subject to a probe over the affair.
HSBC said it was informed yesterday that the investigation had been launched in relation to the conduct of the Swiss bank in 2006 and 2007 for "alleged tax-related offences".
The group said: "HSBC Holdings plc believes the French magistrates' decision is without legal basis and the bail is unwarranted and excessive.
A source told Reuters that magistrates estimated the alleged fraud amounted to about 2.2 billion euro (£1.6 billion) but that HSBC contests the figure. A spokeswoman for HSBC declined to comment on the sum.
Its Swiss bank has already had to deposit a 50 million euro (£36 million) bond with French magistrates.
HSBC chief executive Stuart Gulliver has previously apologised for "unacceptable" activities linked to the bank's Swiss arm in the mid-2000s.
It is accused of helping around 30,000 account holders comprising almost £78 billion to hide these assets from the tax authorities in their home countries.
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