A construction boss is delivering a burst of details about an alleged system of corruption in the construction industry in the Montreal area.

Lino Zambito has told Quebec's public inquiry he was part of a system of collusion and has described a cartel-like system that controls the industry.

His testimony mirrors allegations made three years ago in media reports that triggered demands for an inquiry that is now underway.

Zambito is the first person to describe, in such extensive detail and so publicly, his own personal involvement in construction-related wrongdoing.

His performance at this probe is reminiscent of the role played by Jean Brault at the federal sponsorship inquiry, that of a businessman blowing the whistle on wrongdoing in which he personally participated.

But the scope of the alleged corruption being discussed at the Quebec industry potentially dwarfs the sums involved in the sponsorship scandal that rattled federal politics.