Newly released search warrant documents show that police believe Joël Gauthier, the former head of the Agence métropolitaine de transport (AMT), committed fraud and breach of trust.
Police were notified about "irregularities" in Gauthier's behaviour by the man who replaced him at the transit agency, Nicolas Girard.
Police interviewed several former AMT employees and representatives of engineering firms.
They said that Gauthier routinely accepted hockey tickets and other gifts from those companies, and believe he often solicited the companies to get tickets.
The 42-page document shows that shortly after Bombardier won a maintenance contract with the AMT, Gauthier was a guest in the company's corporate box at the Vancouver Olympics in 2010.
The investigation also found that Gauthier was allegedly soliciting donations for the Quebec Liberal Party right out of his AMT office. Gauthier was the president of the party before he was appointed head of the AMT in 2003.
In one case, an AMT lawyer said Gauthier asked him for a $3,000 donation. The lawyer got his wife to write a cheque to the Liberal Party, and Gauthier reimbursed the full amount.
The search warrant documents also show that Gauthier didn't want people poking around his cellphone records.
A former secretary told police he once asked her to destroy his company cellphone by stomping on it, telling her he didn't want personal information to be seen by the company's IT department.
None of these allegations have been tested in court.
Gauthier, who could not be reached for comment, has not been charged with any crime.