An Ottawa clinic at the centre of a Hepatitis C scare is facing a multi-million-dollar class-action lawsuit, alleging that several patients were infected because of unsafe medical procedures.

Last month, Ottawa Public Health sent out letters to 6,800 patients, warning that they might have been infected by hepatitis C and HIV. Not all have been tested yet, but four people have come forward saying they have tested positive for hepatitis.

The clinic, which is run by Dr. Christiane Farazli, came under suspicion from the local health authority when inspectors found lapses in the way some instruments were being handled. The instruments under suspicion had been used in examinations for stomachs and colons.

Nicholas Robinson, a lawyer who is representing the patients in a class-action suit against the clinic, said that the ordeal has caused panic in the community and distress among patients.

"The people who've received letters indicating they have contacted the illness are extremely distraught. They're upset," Robinson said.

Robinson, from the Merchant Law Group, has launched a $20-million class-action lawsuit, alleging improper care by Farzali. While the hepatits C test results may give the case more weight, Robinson conceded that proving when exactly his clients were infected could be difficult.

"It would be for a judge to decide whether it's more likely, or not, these people got infected by the clinic, or some other source."

And despite the ongoing scare, health officials moved Wednesday to reassure the public.

"I remind people again that the risk of infection related to this lapse is very low," said Dr. Isra Levy, Ottawa's medical officer of health.

In a statement released Wednesday night, Levy said that infected patients will now be interviewed about "any and all possible ways" they may have been infected, including sexual contact, invasive medical procedures, tattooing and body piercing.

Still, health officials believe that more cases will emerge as the testing continues.

Farazli is still practicing but she has been barred from performing the procedures that sparked the lawsuit.

Meanwhile, another patient has come forward with allegations that he was also infected. Carlos Martinez said that his father contracted hepatitis nine years ago after getting a colonoscopy at the Ottawa clinic.

"Weeks later, our family doctor called him for a one-on-one and revealed he was infected with hepatitis C," said Martinez.

Dr. Michael Gardam, from Toronto's University Health Network, said it will be difficult to prove the cases are directly connected to the clinic, because there isn't an established link.

Gardam said that officials can analyze the known cases for similarities, but he tempered the potential analysis with the possibility that some of the patients had hepatitis C before they visited the clinic.

"I'd say it's very likely that they had hepatitis C before," he said, adding that the risks associated with the clinic in question were very small.

"We know that hepatitis C is a relatively common disease out there. If you're going to test 7,000 people, those of us in the business have always thought that you're going to find some positives."

"That doesn't really surprise me," he told CTV News Channel.

Still, despite evidence that medical instruments may have been mishandled at the clinic, Gardam said that Ottawa health officials reported minor documentation lapses and a few small breaches in practice.

In total, Gardam said that safety likely wasn't seriously breached.

"The concept of overkill actually comes from the sterilization world, which is: we kill the bugs so many times, that even if we skimp a bit, we're probably still okay."