Conte is currently serving a 10-month ban following his involvement in the betting scandal while he was the tactician of Siena in Serie B in 2010-11.
However, the suspension applies only to matchday duties, meaning that the Italian is free to train his players on a daily basis.
Zeman, who was appointed the Roma boss earlier this summer following the departure of Luis Enrique, disagrees with this ruling.
"A suspended player can train, but I think a coach with a long-term ban shouldn't be able to train his team," he said at a press conference on Sunday.
"I haven't read the full verdicts of the betting trial, but if people want to weaken this phenomenon then they have to be more decisive."
Roma will begin their 2012-13 Serie A campaign with a home game against Catania later on this month.