A judicial source said the list reportedly containing the details of some 2,000 Greek account holders was finally delivered to a special prosecutor by Stelios Stasinopoulos, the head of Greece's economic crimes unit SDOE.
The discovery took almost a week and the involvement of Greek intelligence and two former finance ministers, some two years after the government is believed to have first received it.
Former finance minister George Papaconstantinou has said the list — part of account data leaked by an HSBC bank employee in Switzerland — was passed on by France's then finance minister Christine Lagarde in 2010.
Greek officials had long maintained that the information had been illegally obtained and could not be used to chase down potential tax dodgers.
Two weeks ago, deputy finance minister George Mavraganis reiterated that the material was the fruit of "industrial espionage" and would not be used.
But facing mounting anger towards ongoing austerity cuts, Athens then reversed its position and Finance Minister Yannis Stournaras said the government wanted to use the information — if only it could be found.
"I first learned of its existence from the newspapers," Stournaras told the Financial Times, adding that if the economic crimes unit could not track the data down "we'll ask our European partners for another copy."
The affair has spawned sarcastic comments in Greek media.
"Everybody knew about the names on the list," said top-selling daily Ta Nea, poking fun at the game of "hide and seek" involving the missing data.
"No official, past or present, is able to give a convincing answer on what has happened with this evidence. But it is clear that checks were not carried out, when other countries were able to deal major blows to tax evasion," Ta Nea said.
Supreme Court prosecutor Nikos Pantelis on Tuesday told reporters that the material was eligible for use "as it came from an official state representative through diplomatic channels."