Parma, January 16 - The former mayor Parma, Pietro Vignali, was among four people placed under house-arrest on Wednesday in a graft probe. Pietro Vignali, a 44-year-old who served as mayor of Parma from 2007 to 2011 on the centre-right ticket, is accused of misappropriation of public money and corruption. Investigators believe he illegally used city money for electoral-campaign spending and was involved in relatives and friends obtaining jobs in public bodies. From 2001 to 2007, Vignali was Parma's executive councillor for environment and transportation. He was forced to resign on September 28, 2011 after a number of city officials and members of his city executive were implicated in a corruption probe. Vignali's resignation led to early elections in May 2012 won by Parma's current mayor, Federico Pizzarotti, a member of comedian Beppe Grillo's anti-establishment Five Star Movement (M5S).