Yanis Varoufakis divulged the details on how Greece could sneak out of the euro "without telling anyone" in a conference call released Monday.

With a plan to secretly append a new bank account to each citizen or company's tax number, Greek officials war-gamed the creation of a parallel system to the single currency, according to the former finance minister. Varoufakis' resignation, 10 days before he made the comments on a call with investors on July 16, leaves open the question of whether the plans have been torn up or just shelved.

Since then, Greece has managed to win some reprieve from the threat of default by agreeing to austerity measures with creditors that the former minister opposed. That said, with Prime Minister Alexis Tsipras' parliamentary majority dwindling, stalling implementation could herald the return of euro-exit talk before long.