Anti-graft prosecutors have summoned the secretary general of the main opposition party in Romania in a notorious case involving former PM Adrian Nastase and his cronies.

Miron Mitrea, who served as Transport minister under Nastase in 2000-2004, is about to become yet another member of the opposition Social Democratic Party who received legal threats or were brought to court under corruption-related charges.

Mitrea has received a bulls eye from the National Anti-Corruption Department (DNA) in the so-called "Zambaccian" real estate case, in which former PM Nastase faces corruption charges covering the period of 2001-2004, according to judicial sources quoted by two TV stations.

According to a DNA note submitted to the House of Deputies, DNA chief Daniel Morar claims Nastase and another high-profile member of his government have ordered and protected a woman, Irina Jianu, as head of an institution supervising construction works. The institution answered to minister Mitrea until 2004.

Irina Jianu is charged with bribing Nastase USD 100,000 in various services and goods for his real estate properties in Bucharest and another town. She was also deputy head of a firm run by a crony of Miron Mitrea, which built a block of flats in downtown Bucharest, on Zambaccian Street, on land owned by Nastase.

Miron Mitrea is currently investigated in two criminal cases. One is related to a contract he signed as a minister with US giant Bechtel to build a highway in Transylvania. The other is focused on a former Romanian Railways head who allegedly offered a motorboat as a bribe to Mitrea.