(AGI) Bologna, Aug 3 - Bologna's deputy prosecutor, Massimiliano Serpi, said the public prosecutor's office is unfazed by Turkish President Recep Tayyip Erdogan's criticism of the city's money-laundering investigation against his son, Bilal. Mr Erdogan condemned the authorities' decision to open the investigation during an interview on Rai News 24. Mr Serpi responded: "We have absolutely nothing to say. We work with serenity and commitment and we're carrying on." With regards to Italy's reaction to Erdogan's words, Mr Serpi said: "Our national institutions and government have taken coherent stances that safeguard Italy's sovereignty and reputation." The inquiry was sparked by a complaint filed by a member of a family opposed to Mr Erdogan's conservative and Islamic AKP (Justice and Development) party. This person currently lives in an EU state as a political refugee. In the complaint, Bologna's prosecutors were asked to inspect sums of money allegedly transfered to Italy by Bilal Erdogan as part of a money-laundering scheme. In July, six months after the preliminary investigation was launched, a Bologna judge approved the public prosecutor's request to extend the investigation. It was based on the need to carry out verifications abroad and the workload assigned to the judicial police for completing the task. Bilal Erdogan arrived in Bologna in the autumn of 2015 to continue his studies at John Hopkins University, and left Italy in March this year. (AGI). .