About 50 investigators from the province’s anti-corruption unit (UPAC) raided the Quebec City headquarters of engineering consulting firm Roche early Wednesday morning.

The investigators began searching through Roche’s documents at approximately 6:30 a.m. ET.

UPAC spokeswoman Anne-Frédérick Laurence said no arrests are expected for now, but investigators will be questioning some employees.

"The elements of this search, as well as the motives of the investigation, are of a confidential nature," Laurence said.

Similar searches under Operation Hammer took place at Roche’s Montreal and Quebec City offices in 2010. At the time, officers were looking for proof of allegations of fraud and breach of trust in the construction industry.

Operation Hammer was formed in 2009 to investigate corruption in the construction industryUPAC was created two years later, in early 2011.

Roche has been mentioned at the Charbonneau Commission, the province’s inquiry into corruption in the construction industry. In 2012, a former Roche employee alleged that some of his former co-workers had engaged in bribery in bid-rigging.

UPAC at Roche

UPAC investigators arrived early Wednesday morning to search for documents at Roche's HQ in Quebec City. (Jean-Francois Nadeau/Radio-Canada)