A former senior trader at Credit Suisse has been arrested in London on fraud charges and may be extradited to the US.
According to the BBC, Kareem Serageldin was dismissed from the bank in 2008 along with two colleagues.
In February, David Higgs and Salmaan Siddiqui pleaded guilty to charges of wire fraud and falsifying books and records.
They said Serageldin directed them to manipulate prices of mortgage-backed securities to cover up losses.
Serageldin, who is a US citizen, will appear before magistrates on Thursday.