Serie A title contenders Napoli and captain Paolo Cannavaro were ordered by the Italian soccer federation on Friday to face match-fixing allegations.
Current and former Napoli players Gianluca Grava and Matteo Gianello and former Napoli assistant coach Silvio Giusti were also called in for questioning over the May 16, 2010, Sampdoria-Napoli match.
Sampdoria won the match 1-0 with a goal from current AC Milan player Giampaolo Pazzini in the 51st minute. The victory secured Sampdoria fourth place and a spot in Champions League qualifying.
Gianello and Giusti are accused of sports fraud by attempting to fix the match in exchange for money, while Cannavaro and Grava are accused of failing to report fixing.
Cannavaro is the younger brother of former Italy captain Fabio Cannavaro.
Napoli could be deducted points and the players could be banned if found guilty.
Several others were also called in for questioning over alleged fixing in the lower-division Portogruaro-Crotone match in May last year.
The accusations stem from an investigation by Naples prosecutors.
Gianello told prosecutors in June of last year, and then confirmed to federation officials, that Giusti attempted to fix the match and asked Cannavaro and Grava to help, according to the ANSA news agency. Cannavaro and Grava allegedly refused to take part in the fix but they did not report it.
Napoli trail Serie A leaders Juventus by three points, as the club chases its first title since 1990.
Four Serie A clubs have already been docked points this season for match-fixing. Siena were penalized six points, Atalanta two, and Sampdoria and Torino one each.
At least 50 people have been arrested for match-fixing since the middle of last year, with scores more under investigation by prosecutors in Cremona, Bari and Naples.