Former Romanian Prime Minister Adrian Nastase has been questioned by prosecutors investigating his property purchases amid corruption allegations.
Mr Nastase's property deals are under scrutiny
Mr Nastase resigned as leader of the opposition Social Democratic Party on Monday. He is also under pressure to quit as Speaker of parliament.
It is a preliminary investigation and no charges have been laid against him, the prosecutors' spokeswoman said.
Mr Nastase has denied any wrongdoing, describing the inquiry as political.
Romania is under close European Union scrutiny as it works to join the EU as planned in early 2007.
The country has long been criticised by EU officials for failing to tackle corruption at the top.
Mr Nastase was prime minister from 2001 to 2004.
Public officials in Romania are obliged to make public detailed accounts of their wealth.
Attention in this case is focused on properties worth more than $1m which Mr Nastase says he inherited from an aunt of his wife's.
He bowed to pressure within his own party to step down temporarily to answer the allegations.