London trader faces Interpol over Greek debt email
The Greek authorities have asked Interpol to question a London trader over an email he sent which talked of the high chance of a Greek default.
The email, published in a Greek newspaper, refers to "increased noise" over a Greek debt restructuring as early as Easter.
Greece is highly sensitive to allegations it may not stick to strict repayment terms on its recent bail-out.
The finance ministry says the incident amounts to "possible criminal conduct".
Greek police say the email was sent from the desk of a Citibank trader in London.
Citibank said in a statement: "We are co-operating with the authorities and do not consider there to have been any wrongdoing by Citi or its employees."
Speculation Greece will default and fail to pay back its borrowings has pushed interest rates on debts due for repayment in 10 years to 15%, meaning it has to pay almost 12% more to raise cash than its fellow eurozone member, Germany.
Bonds that are due for repayment in two years were paying 23%, indicating that investors thought they were even less likely to be paid back in full.
On Wednesday, Athens' main stock index dropped 2.6% on a new wave of fears.
Greece's Finance Minister George Papaconstantinou insisted on Wednesday that Greece could deal with its debt mountain.
The country was the first of three to ask for special help from the European Union and its partners after it became clear a year ago that it could not close the gap between spending and borrowing.
Greece's attempts to regain international trust in its finances have already included public sector cuts that have sparked massive demonstrations.
Last week it announced a privatisation programme to raise 50bn euros ($71.5bn; £44bn).