One of HSBC's top executives has been arrested and charged with fraud in the US following a foreign exchange investigation.
Mark Johnson, the bank's global head of forex trading was arrested on Tuesday, as was a former colleague, Stuart Scott.
The US Department of Justice (DoJ) has accused the pair of "front-running" - using confidential information given by a client. Mr Johnson and Mr Scott are accused of profiting from a $3.5 billion (£2.6bn) foreign exchange deal in 2011.
It is thought the two men bought sterling before handling the deal themselves, knowing that such a large transaction would see the value of the pound increase, allowing them to sell at a profit.
Following a court hearing on Wednesday, Mr Johnson - a Brit who lives in the States - was released on bail for $1m.
HSBC said it does not comment on individual employees, but confirmed it would work with the DoJ on its investigation.
US Attorney Robert Capers said: "The charges and arrest announced today reflect our steadfast commitment to hold accountable corporate executives and licensed professionals who use their positions to fraudulently enrich themselves."
"It was advantageous to them and HSBC, and disadvantageous to the victim company, to execute the victim company foreign exchange transaction" at that specific time, the DoJ said.
The currency deal resulted in an estimated $8m profit for HSBC, the DoJ claimed.
HSBC was one of six banks fined by British and US regulators over their traders' efforts to manipulate foreign exchange rates in 2014.