A parliament committee on Wednesday authorized judicial authorities to investigate Yiannos Papantoniou for failing to declare the sum of 1.3 million euros ($1.7 million), the state-run Athens News Agency reported on Thursday.
Prosecutors have already ordered a general investigation into Papantoniou's bank holdings.
One of Greece's longest-serving finance ministers who also headed the defence ministry, Papantoniou maintains that the Swiss account belongs to his wife.
The account in question is one of over 2,000 included on the so-called Lagarde list, a document which France's ex-finance minister and current IMF chief Christine Lagarde gave to Greek authorities in 2010 to help a tax evasion probe.
A succession of Greek finance ministers have faced criticism in recent months for failing to properly screen the data, which had been originally leaked by an HSBC employee in Geneva and has been used by a number of European states to crack down on tax cheats.
Earlier this month, parliament authorised an investigation into former socialist finance minister George Papaconstantinou, who is accused of removing the names of three of his relatives from the list.
Papaconstantinou has denied the charge, countering that the fight against chronic tax evasion in Greece actually intensified during his term.