A so-called DP junta to decide Ignazio Marino's fate began on Capitoline Hill at 11:00 GMT and has not concluded yet, according to the Corriere dello Sport daily.
A high-profile scandal erupted this week when Marino was found to have misappropriated municipal funds for his own gain.
On Tuesday, Rome prosecutors began investigating claims that Marino had allegedly used an official credit card to discharge personal expenses. The allegations were first raised by Five Star Movement and the Brothers of Italy opposition parties.
In response to the backlash, Marino pledged on his Facebook page to pay back 20,000 euros ($22,500), which he claimed to have spent for the benefit of the city.
The scandal erupted after Marino published his expenses in a display of his commitment to transparency.
Other outlets cited sources as saying the embattled mayor may announce his resignation as soon as Thursday and the next mayoral elections may take place next spring.