The agency made the announcement on Tuesday.
The company's website says it performs quality control testing for a variety of products, including drugs, food and cosmetics.
Health Canada said companies that had products tested at the Mississauga facility are being asked to temporarily suspend sales until it can confirm the safety of products.
"There was a number of schemes that were used by the company to falsify test results," alleged Paul Glover, assistant deputy minister of the health products and food branch, during news conference.
Testing was done but not always, he said.
"Tests were made up, fabricated. Other times they were released before tests were actually completed," he alleged.
The products ranged from veterinary drugs to natural health products and ingredients potentially used in food, cosmetics and medications for the treatment of high blood pressure and diabetes. (See the list by clicking the Health Canada link in the right column.)
Health Canada inspectors uncovered problems during a regular inspection. Chemi Pharmaceutical was asked to take corrective actions, but when an inspector received a phone tip, a regulatory team performed a surprise visit and gathered evidence suggesting a pattern of falsifying records, the agency said.
Manufacturers need to retest products to ensure safety, officials said. If any problems turn up, then recalls may be required.
Worker has since been fired
Chemi president Mariana Stavrikov acknowledged to The Canadian Press that records had been falsified, but stressed that it was an employee who did the tampering without the company's knowledge.
The employee has since been fired, she said, adding that the man came forward himself and also admitted that he alerted Health Canada.
Stavrikov said the man — one of 24 workers at the firm — was not a longtime worker. She did not give his name.
"All the results that had been falsified were done by him.… What this shows is that one sabotager can sabotage the system," she said. "The products are safe. We've committed to retest all [the products]."
Health Canada said its survey of the company's clients indicated that only a portion of the tests were for final products.
Officials said that other manufacturers are available for the blood pressure and diabetes medications.
So far, 53 products and ingredients need to be retested. The agency is gathering more information about another 25 products or ingredients.
Health Canada called the alleged falsification of documents unprecedented. Law enforcement officials, including the RCMP, have been informed about Health Canada's findings.
Septa Pharmaceuticals Inc., which had tested products at Chemi Pharmaceutical, said in a statement on Tuesday that it was notified the previous night about the suspension of the testing lab's licence.
Septa said it was temporarily halting distribution of products tested at Chemi Pharmaceuticals while it investigates whether recent products were released for sale.
"We do not believe our products to be affected by the issues that are facing Chemi Pharmaceuticals," the company said, adding that initial tests are conducted outside of Canada and that Chemi Pharmaceuticals only performed "confirmatory test results."
"We are truly shocked at what has transpired," the statement said.
Septa is looking for a new testing laboratory.Suggest a correction