Former Financial Crimes Squad (SDOE) chief Yiannis Diotis is to appear before financial prosecutors on Tuesday to answer questions regarding his handling of the Lagarde list.

Earlier, it had been suggested that Diotis might face prosecutors Spyros Mouzakitis and Grigoris Peponis on Monday.

Diotis is seen as a key figure in the investigation after a forensic examination of the USB stick containing the list of Greek depositors, which had been given to prosecutors by PASOK leader and ex-Finance Minister Evangelos Venizelos, revealed that the data had been transferred onto the device on July 8, 2011.

At the time the flash drive is thought to have been in SDOE’s possession. Diotis had succeeded Kapeleris by that time.

Prosecutors are trying to find out who doctored the information to remove accounts belonging to three of Papconstantinou’s relatives.

On Thursday MPs will vote on whether Papaconstantinou, Venizelos and ex-prime ministers George Papandreou and Lucas Papademos should be investigated by a parliamentary committee.

Earlier on Monday, Diotis’s predecessor, Yiannis Kapeleris, told prosecutors that he never received the Lagarde list from Papaconstantinou.

Kapeleris submitted a written deposition to financial prosecutors Grigoris Peponis and Spyros Mouzakitis, who are also expected to quiz his successor, Yiannis Diotis, for a second time on Monday.

Sources said Kapeleris insisted he was not given a CD or memory stick containing the list of some 2,000 Greek depositors at the Geneva branch of HSBC. He said that he was give a single sheet of paper that was a printout, which he could not use to investigate suspicions of tax evasion.

Kapeleris said he returned the document to Papaconstantinou.