Signori held in match-fixing probe
The Italian Football Federation (FIGC) told Reuters it would open an inquiry after Atalanta and Siena, due to be promoted to Serie A next season, were named as being among the clubs under the spotlight.
Domestic football has been battling corruption for years with the fallout from a major 2006 match-fix scandal in the top flight still rumbling on in the criminal and sporting courts.
"State police from Cremona, collaborating with police departments in Bari, Como, Bologna, Rimini, Pescara, Ancona, Ascoli Piceno, Ravenna, Benevento, Roma, Torino, Napoli and Ferrara have carried out 16 arrests," said a police statement on Wednesday.
"(This) follows an investigation into a series of episodes connected to match-fixing which in past months has significantly influenced the results of some matches in Serie B and Lega Pro [lower division]."
Former Lazio captain Signori has been placed under house arrest with seven others while another seven have been held in prison following the six-month probe.
A further request has been made to arrest another of the accused who is outside Italy, according to a police source.
"As well as the arrests there are another 28 people under investigation including footballers of a certain standing still playing," said the source who declined to be identified.
"The investigative procedure," the police statement continued, "was able to collect important and irrefutable evidence to demonstrate the existence of an organised crime group composing footballers, ex-footballers of international standing, bookmakers and other individuals.
"Each, with specific and pre-determined roles, were able to plan through verbal agreements or payments the fixing of some football matches.
"[There was] a serious incident on the occasion of a football match that took place at the end of last year (in Cremona)," the statement read.
"The investigation revealed criminal behaviour in a wider context linked to several people in the footballing world who, because of direct and indirect contacts, were able to influence the results of several matches and thereby make a payment of large sums of money through legal betting networks in Italy and abroad."
Signori scored 188 Serie A goals, winning 28 caps for Italy, in an illustrious career.
Former Bari captain Antonio Bellavista, Benevento goalkeeper Marco Paoloni, former AC Milan player Mauro Bressan and Ravenna sporting director Giorgio Buffone were among those held in jail.
The revelations come just a day after prosecutors in Italy's long-running 'calciopoli' trial requested former Juventus general manager Luciano Moggi face five years and eight months in jail if found guilty for his involvement in the 2006 match-fix scandal.
Juventus were demoted to Serie B in 2006 and had their 2005 and 2006 Serie A titles stripped after being punished in the sporting courts for trying to gain favourable referees for their matches.