Stavros Papastavrou, an adviser to former prime minister Antonis Samaras, has been invited by a prosecutor to answer questions on Wednesday regarding his appearance on the Lagarde list of Greeks with deposits at the Geneva branch of HSBC.
Prosecutor Yiannis Dragatsis called Papastavrou, a lawyer, to explain why his name was linked to an account containing 5.5 million euros.
The account was among hundreds on a stolen list submitted to the Greek authorities in 2010 by then-French finance minister Christine Lagarde, currently managing director of the International Monetary Fund.
Papastavrou insists that he is innocent of any wrongdoing and that the money is related to the business activities of a client of his, Greek-Israeli businessman Sabby Mionis.
The financier, who also denies any wrongdoing, has been asked to provide documentation relating to the large deposits at HSBC.