Milan, February 21 - Italian police said on Thursday that they had detained Admir Suljic, a 31-year-old Slovenian who is suspected of being a senior figure in a major international match-fixing ring. Investigators said Suljic is a key element in one of a series of probes into betting-related match-fixing in Italian soccer in recent years. Over 40 people have been arrested since the the first of the probes, the Cremona-based 'Last Bet' criminal investigation, went public in 2011, leading sporting prosecutors to look at the case. They include Lazio midfielder Stefano Mauri and former Italy internationals Beppe Signori and Cristiano Doni. Four Serie A sides started this season with points deducted because of their players' involvement - Siena (-6), Atalanta (-2), Torino (-1) and Sampdoria (-1). In December Juventus boss Antonio Conte finished serving a four-month ban for failing to report a deal to fix a match during his time at former club Siena. Suljic, who was arrested upon landing in Milan after a flight from Singapore, is an alleged associate of alleged soccer matchfixing kingpin Tan Seet Eng. Tan is a Singapore national. Europol, the European anti-crime agency, said earlier this month that it had identified about 680 suspicious matches including qualifying games for the World Cup the European Champions League. The new case has rocked the Italian soccer world again after Juventus were relegated and stripped of two Serie A titles for involvement in the Calciopoli match-fixing scandal in 2006. That scandal regarded schemes to have compliant referees officiate some teams' matches.