Bridges said it's already in the hands of the Serious Fraud Office, and the Minister would have been well briefed before that occurred.
Harrison has now reportedly skipped town - and is possibly in Canada.
The Serious Fraud Office has launched an investigation, it confirmed last night.
New Ministry of Transport head Peter Mersi said the staff member involved was in a position of "high trust" and the organisation had felt incredibly let down and betrayed by her actions.
"I can confirm that, following investigations into allegations of significant breaches of the Code of Conduct by former staff member Joanne Harrison, a complaint has been laid with the Serious Fraud Office," Mersi said.
"In light of what has happened, it is prudent to confirm that our systems, processes and controls are robust. To provide this assurance, a number of reviews are now underway. These focus on internal controls and recruitment processes."
Harrison had worked at the Ministry for several years and had been seen as a leader within the organisation - being appointed the general manager of organisational development for the team.
- Additional reporting: Newstalk ZB