The first round in what is likely to become an extended bout of complex legal manoeuvring takes place tomorrow, when Mr Leeson, 28, will fight a request for his extradition to Singapore at a closed court hearing in Frankfurt.
The Singapore authorities are determined to bring him back to their country for trial on charges of fraud and forgery. But Mr Leeson is equally determined not to go, because he could face up to 30 years' imprisonment.
His British lawyer, Stephen Pollard of Kingsley Napley, said last week that Mr Leeson might be willing to help the UK authorities to formulate charges against him so that Britain could also apply for his extradition. His co-operation will probably be essential because an extradition request must be lodged with the German courts within a month.
The various official investigations, by the Serious Fraud Office, the Bank of England and Barings itself, are likely to take considerably longer than that to come up with hard evidence with which to charge anyone in the affair.
There are hopes that a trial in the UK would uncover more of what happened in the disaster than a Singapore trial would.
Legal experts believe that, given a choice between extraditing Mr Leeson to Singapore or Britain, the German courts will choose the latter, because of European ties.
Meanwhile, senior Barings executives connected with the affair, including Peter Norris, head of investment banking, and Ron Baker, head of derivatives, will continue to turn up for work at Barings as well as talking to the various investigators. "Everyone here is innocent until proved guilty," said Aad Jacobs.