ATHENS, Greece — Greece’s government on Monday launched complex bailout negotiations with creditors, but faced rebuke following revelations that former finance minister, Yanis Varoufakis, formed a secret committee to plan for the possible conversion of euros into drachmas “at a drop of a hat.”

Finance Minister Euclid Tsakalotos said late Monday that meetings in Athens had begun between Greek officials and negotiating teams representing creditors, with talks to intensify Tuesday, paving the way for higher level discussions possibly by the end of the week.

Before the talks started in Athens, a recording of Varoufakis discussing a parallel currency plan was made public.

Opposition parties have criticized Varoufakis and have urged Prime Minister Alexis Tsipras to explain what he knew of his former finance minister’s actions.

In the recording of a telephone briefing for investors on July 16 in the wake of his resignation days earlier, Varoufakis claimed he and a computer expert hacked into his ministry’s computer systems as a step to creating “a parallel banking system.”

The Greek banks were closed on June 29 to avoid a bank run amid fears that Greece was heading for a euro exit. In theory, a parallel system formed from the effective cloning of tax accounts would have allowed the finance ministry to continue payments in the form of so-called IOUs.