Following a series of developments in the Lagarde list probe that suggest the existence of at least three memory sticks containing the details of some 2,000 Greeks with deposits at a Swiss branch of HSBC, authorities are hoping that the additional testimony former Financial Crimes Squad (SDOE) chief, Yiannis Diotis, is to give on Monday will shed some light on the affair.

Prosecutors said on Thursday that the data on a USB stick in their possession had been copied onto the device in July 2011, after former Finance Minister Giorgos Papaconstantinou left office but before his successor, current PASOK chief Evangelos Venizelos, received the data from Diotis.

Meanwhile investigative journalist Costas Vaxevanis claimed the flash drive he has was created in August 2010, before Papaconstantinou claims to have received a CD with the list from French authorities. Vaxevanis gave his device to Supreme Court vice prosecutor Nikos Pantelis.

Prosecutors are said to have drawn two key conclusions – firstly that the original CD given to Papaconstantinou has been lost and secondly that at least three copies of a USB stick containing the list data were created.

One is in the hands of prosecutors, the second was given by Vaxevanis to Pantelis and the third – the original – remains unaccounted for. As Papaconstantinou copied the data from the original CD to a memory stick which he gave to SDOE – and cannot account for either – he remains under suspicion for tampering.

A copy of the original list given to Greek authorities by the French last month contained 2,062 names, three more than on the flash drive being probed by prosecutors. The trio are relatives of Papaconstantinou.

Complicating matters, a member of the police’s electronic crimes squad told Pantelis that the date on a memory stick can easily be changed and should not form the basis for sound conclusions.

Parliament is to vote on whether Papaconstantinou, Venizelos (and former premiers Lucas Papademos and George Papandreou) should be the focus of an inquiry into the handling of the Lagarde list on January 17 irrespective of the lack of progress in the prosecutors’ probe.