A Seattle hospital has joined a lawsuit against the manufacturer of endoscopy medical scopes linked to a "superbug" outbreak at the medical center, claiming the company, Olympus America, put patients lives at risk by failing to disclose design flaws.

Between 2012 and 2014, at least 32 patients at Virginia Mason Medical Center were infected with strains of multidrug-resistant E. coli bacteria spread through contaminated scopes that had been sterilized to the manufacturer's guidelines, according to state health officials.

At least 11 people eventually died, though the role of the superbug in their demise was unclear because all the patients were critically ill at the time of their infection, Washington state public health officials said.

In March, the wife of one of the deceased, Theresa Bigler, filed a lawsuit against Olympus America, part of Olympus Corp. Bigler said her husband, Richard Bigler, died in 2013 from pancreatic cancer and an E. coli bacterial infection contracted from one of the company's faulty medical scopes.

On Monday, Virginia Mason said it had joined Bigler's lawsuit because Olympus America knew its duodenoscopes, which are used to treat illness in the pancreas and bile ducts, could harbor germs even after being cleaned to manufacturer and federal guidelines.

"Olympus failed to inform our organization about this safety risk associated with its product," said Andrew Ross, the head of gastroenterology at Virginia Mason. "Their silence on this important issue was unethical, irresponsible and put patient lives at risk."

Bigler's original lawsuit also named Virginia Mason for deciding not to tell people who had undergone procedures with the scopes that they might have been infected. It took hospital officials two years to pinpoint the source of the contamination.

Her attorney, John Gagliardi, told a news conference on Monday that the hospital has since changed course and begun notifying those possibly exposed.

Olympus America said in a statement it was "taking this matter extremely seriously."

"We are continuing our investigation into the reports at Virginia Mason to be able to provide a more thorough and balanced perspective on the issues including potential causes of the infections," spokesman Mark Miller said.

It said it was working with authorities, including the Food and Drug Administration, which regulates the medical devices, to "enhance safeguards" with respect to sterilization.

Top makers of the scopes include Olympus Corp, Fujifilm Holdings Corp and Pentax.