The Toronto Transit Commission says it has fired four more employees in connection with an alleged benefits fraud scheme involving a Toronto-based orthotics company.

In July, Toronto police laid several charges against the owner of Healthy Fit, a company that provides orthotics products to some TTC employees. The company allegedly convinced transit employees to file claims for orthotics that were never purchased and provided receipts that inflated the cost of products that were bought.

The commission alleged in July that the transit employees making fraudulent claims would then share the money paid out by the TTC’s insurer, Manulife Financial, with members of Healthy Fit.

Investigators said the alleged fraud scheme was discovered with the help of a tip life set up by the TTC in 2013 called “Integrity.”

The owner of Healthy Fit and two of the company’s employees were charged with fraud over $5,000 and possession of the proceeds of crime in July.

The alleged scam cost the transit commission and Manulife a total of $4 million.

In October, the TTC dismissed one of its supervisors, who was allegedly involved in the scam.

In a statement released Wednesday, the commission announcement four more employees have been fired.

“It’s only right that we take a very tough line on dealing with this matter,” TTC CEO Andy Byford said in the statement. “Not only does this put our benefits package at risk, it also undermines the credibility and honesty of each and every one of us in the eyes of the public, just as we are working so hard to restore our reputation.”

The TTC said it is working closely with Manulife Financial to strengthen its fraud detection programs.

“The TTC is determined to work with the health benefit industry in an effort to ensure that adequate and proper fraud preventions systems are in place,” the statement said. “The TTC takes the responsibility it has to protect public money extremely seriously.”