It began with a bout of poisoning and now includes police officers having launched a dawn raid on the Italian national team's training camp.

The calcioscommesse scandal moved into a new phase with yesterday morning's developments at Coverciano, the Tuscany base where the Italian squad is preparing for Euro 2012 and where Italian managers earn their qualifications. It is in many ways the heart of the Italian game, so it could never be immune from the darkest impulses of the national sport.

Officers searched the room of Domenico Criscito, the former Genoa defender who now players for Zenit St Petersburg, and informed him that he faces questioning as part of an ongoing investigation into gambling on fixed results. The 6.40am raid was part of a concerted effort that led to 17 arrests across Italy, 11 of them players – including the Lazio captain, Stefano Mauri and the former Genoa captain, Omar Milanetto, who were detained on allegations of "criminal association and sporting fraud".

Police officers also informed Antonio Conte, whose Juventus side won Serie A, that he is under investigation from his time in charge of Siena. Leonardo Bonucci, the Juventus and Italy defender who was once at Bari, is also under investigation, while 31 homes in Italy and abroad were searched yesterday.

Criscito was expected to be named in Cesare Prandelli's provisional Euro 2012 squad of 27, with the final selection decisions to be made following tonight's friendly against Luxembourg, but he was dropped following the police raid; Bonucci still remains in the squad for now. Criscito maintains his innocence, as does Conte, who has been implicated because prosecutors believe that he was aware that two Siena matches were fixed, even though he is not accused of being directly involved. "Conte's reaction is that of someone who's completely innocent and strongly determined to prove his total innocence," said Antonio de Rencis, the Juventus manager's lawyer.

The Italian game has become accustomed to stories of match-fixing, gambling, and bribery, and when the preparations for a major international tournament were interrupted by the Calciopoli affair in 2006, Italy went on to win the World Cup. Yesterday's developments have restored the latest scandal to the forefront of Italian life, but the extent and the reach of the affair has long been suspected.

It was a game between Cremonese and Paganese in Serie C in November 2010 that first prompted the investigation, after allegations that the Cremonese players were poisoned with a sleeping drug. Prosecutors in Cremona discovered that it was an attempt to fix the result of the game because of bets place on the outcome, and then began to uncover a web of deceit that has incriminated many Italian football figures, including Beppe Signori, the former Lazio striker, and Cristiano Doni, the Atalanta captain.

Prosecutors believe the betting scam started when players were paid for information about 'concordate' games, matches at the end of a season when teams unofficially play out a result that suits them both, However, it then spread to the results of other games being influenced, leading prosecutors to The Gypsies, an Eastern European crime gang. In May 2011, Criscito was photographed by police during lunch at a Genona restaurant with Guiseppe Sculli, a Genoa team-mate whose uncle is said to be a mafia boss, two members of the club's Ultra fans group and a Bosnian criminal.

The investigation initially focused on Serie B games, but now extends to teams in the top-flight. Matches involving Bari, Lecce, Lazio, Genoa, Sampdoria, Brescia and Napoli are all under investigation, and evidence has been gathered through phone tapping and interviews. Journalists in Italy expect some of the arrested players to confess, at least to the lesser charge of knowing about the match-fixing (which often included how many goals were scored in a match) but did not do anything about it, which results in one year's disqualification, but also that team executives will be brought into the scandal. Yet nobody believes that the scandal will affect Italy's preparations for Euro 2012.

"Cremona Prosecutor Roberto Di Martino assured us that no other national team players are involved," says Alex Frosio, a reporter with La Gazzetta dello Sport. "Paradoxically, there could be a positive impact: in 2006, the Calciopoli scandal gave a boost to the team instead of depressing it. The national team is very protected."

In Italy, there is a sense of pragmatism about the arrests yesterday. The investigation has been ongoing for almost two years and the expectation was always that it would implicate more leading figures from the game. The ramifications of the Calciopoli scandal that brought Juventus' demotion to Serie B are still keenly felt, but the wider reputation of Italian football is being affected by the strain of constant revelations.

"It is a devastating story," said Giovanni Trapattoni, the former Italy and Juventus manager who is now leading the Republic of Ireland to Euro 2012, where they will face the Azzurri in Group C. "If the magistrates are doing something, it is because there is some truth in this. I, who have travelled abroad for some time, must say that we give an ugly image of our football. As an Italian, the first feeling is that we are mocked abroad, we are always linked to illicit dealings and are considered mafia members. This only damages us because I can claim to have paid the price for an attitude that affects everyone."