The party's corruption watchdog, the Central Commission for Discipline Inspection, said Ji Jianye has been placed under investigation for "suspected severe violations of discipline and law." The one-sentence announcement offered no details, but the term is a euphemism for bribery, embezzlement and other forms of corruption.
Ji's position is equivalent to that of a vice minister, making him one of the highest-ranking officials to be pulled in by the anti-corruption drive since President Xi was installed as party chief last fall.
Former Politburo member Bo Xilai, an even-higher level official convicted of corruption last month, was arrested under the previous administration, though he has often been lumped in with the current anti-corruption drive. Other prominent recent targets have included the head of the Cabinet commission overseeing state-run companies, along with other high officials in provincial and central government and state run industries.
Such internal party investigations often last months before the subject is sent for criminal prosecution and a court trial resulting in an almost certain guilty verdict.
Ji's official resume shows he spent his entire career climbing the ladder of the party apparatus in relatively wealthy Jiangsu province, of which Nanjing is the capital.
However, beginning in 2009, Ji's term as Nanjing mayor was marred by controversy, including rare street protests over the mass removal of the city's beloved plane trees for a subway construction project.
The website of the party mouthpiece People's Daily newspaper said Ji was being investigated over his relationship with a high-profile Jiangsu construction magnate now in detention. It said Ji had a reputation for steering lucrative government development contracts to friends and associates and put the figure for funds involved in his case at 20 million yuan ($3.2 million).