Others named Monday included former Lazio captain Giuseppe Signori, current Lazio captain Stefano Mauri and former Atalanta captain Cristiano Doni " who were each arrested and have each been handed sports bans.
Conte is accused of involvement in fixing matches at the end of the season when Siena had already clinched promotion to Serie A and other clubs were still fighting to qualify for a playoff.
Conte, who has denied wrongdoing, already served a four-month sports ban in the case during the 2012-13 season when he was with Juventus.
For Conte, the prosecutor is examining the Novara-Siena match on May 1, 2011 (which ended 2-2) and Albinoleffe-Siena (1-0) on May 29, 2011.
Conte has also been investigated for fixing when he coached Bari from 2007 to 2009, and the southern club was penalized a point during the 2013-14 season.
Colantuono is being investigated for a Crotone-Atalanta match in April, 2011 that ended 2-2.