The former vice-president of the construction firm Infrabec was accused of making illegal donations to the former mayor's party. He pleaded guilty today in a St-Jerôme courtroom.
He was arrested as part of Opération Marteau in 2011, the first major police operation targeting corruption and collusion.
The mayor of Boisbriand, Sylvie St-Jean, and engineers with the engineering-consulting firm Roche and BPR-Triax, were also arrested.
A year later, Zambito decided to work with investigators. Over several days, he explained to the Charbonneau commission how a cartel of companies split up contracts in Montreal and Laval.
He revealed that businessmen were paying kickbacks to municipal parties in power and paying a percentage of their earnings to the Mafia.
The crimes Zambito pleaded guilty to could earn him jail time, but his collaboration with the judicial system and his frank testimony has many anticipating a lenient sentence.
St-Jean, who pleaded guilty in 2014, was sentenced to two years less a day and was allowed to serve her time in the community.
Zambito is the first entrepreneur to enter a guilty plea.