A batch of Cold-FX cold remedy contaminated three years ago by E. coli-related bacteria and sold to the public may still be on store shelves, a CBC Marketplace investigation reveals.

In 2008, a liquid version of Cold-FX was produced. But when the ginseng powder that goes inside the capsules was combined with the sugary syrup ingredient, it multiplied existing bacteria in the COLD FX powder.

Around 375,000 bottles of liquid Cold-FX had to be destroyed, but the company decided that the batches of contaminated powder left over and other batches from that year could be sold.

Marketplace recently found bottles on the shelves that had been manufactured in 2008 when the product was contaminated.

The pharmaceutical giant Valeant, which bought out Cold-FX from Afexa Life Sciences in 2011, confirmed to Marketplace in writing that there was contamination of powder back in 2008 but that it was "benign E. hermannii," a cousin of E.coli.

The makers of the drug said an "assessment of the risk" was conducted. Valeant says it stands by the safety of the product and even used the powder for a Cold-FX clinical trial on leukemia patients in 2008-2009. Valeant said the principle investigator of those trials, Dr. Kevin High of Wake Forest Baptist Medical Centre in North Carolina, wrote that he didn't think "any of these cousins of E. coli are likely to cause illness" at the low levels found.

Valeant also said that Health Canada agreed with that assessment.

Health Canada told Marketplace that it tested a sampling of the product in 2008 after receiving a complaint from the public.

Health Canada said Cold-FX did not alert them to any problems with the product, but the company did co-operate with Health Canada once contacted.

Health Canada said its testing did identify low levels of bacteria in the samples, but the levels were low enough that they did not pose a health risk.

Dr. Lynora Saxinger, an infectious disease expert at the University of Alberta, said while E. hermannii is considered low risk, it could make people with compromised immune systems sick.

She said that "finding E. hermannii in a natural product would again suggest that there’s been some exposure of the product to fecal contamination."

"When people buy a product, I think they should feel assured that there's not been sewage contamination earlier in the process that got through to that stage," she added.

Health Canada first told Marketplace that the presence of E. hermannii "in a finished natural health product would be unacceptable."

Marketplace also uncovered that Cold-FX, which is marketed as being "proudly Canadian" is processed in two factories in China. Raw ginseng is turned into Cold-FX powder and then shipped to Canada where the powder is put in gel capsules and bottled.

Marketplace obtained an audit that was conducted five years ago on one of the factories.

The audit warned the company not to use the factory.

"In general, the facility is quite dirty ... The current layout results in crossover of materials leading to greater potential for cross-contamination," the audit said. It also pointed out "the potential contamination risks associated with ... open windows to the outdoor environment."