As thousands of people again took to the streets demanding the overhaul of a political system they see as corrupt, President Klaus Iohannis said the country may hold early elections or seek to form a government of technocrats.
Ponta who resigned on Wednesday after huge street protests sparked by a deadly nightclub fire, appeared at the High Court of Justice for a preliminary hearing on charges of fraud, tax evasion and money laundering.
The charges related to a period between 2007 and 2011 when he was working as a lawyer, before he became premier in 2012.
The 43-year-old former Social Democrat leader, who denies the charges, ignored questions from the large media scrum that greeted him at the court.
Friday's hearing was focused on procedural matters and dealing with lawyers' requests, a court spokesman said. No date has been set for the start of the trial, which is expected to open in the coming weeks.
Prosecutors also suspect Ponta of conflict of interest while in government, but that probe was stymied when parliament -- where his Social Democrat party holds a comfortable majority -- refused to lift his immunity from prosecution.
While he is no longer premier, Ponta remains a member of parliament and continues to enjoy immunity.