The Swiss medical devices company, Sulzer Medica, has seen its shares hammered over a faulty product produced by someone else.
Shares in Medica plummeted by more than 20 per cent on Friday to SFr137.50 ($86) following news that a faulty heart valve tester, mistakenly thought to have been produced by one of Medica's subsidiaries, was implicated in the death of a patient in northern England.
The shares later recovered once the markets realised the tester was not a Medica product.
The confusion arose because Medica's subsidiary Sulzer Carbomedics delivers the tester to hospitals along with its own mechanical heart valves. A spokeswoman told swissinfo the tester was manufactured by another firm but declined to name it.
The tester was made specifically for use with Sulzer Carbomedics' bileaflet heart valve.
Three weeks ago a patient died after one of the testers, being used to check implanted mechanical heart valves, broke during a procedure at a hospital in Sheffield.
The British health authorities have launched an investigation into whether the incident may have contributed to the patient's death.
A Medica spokeswoman, Beatrice Tschanz, told swissinfo that the company had "informed hospitals of the incident and ordered that the instrumentation used in heart surgery be monitored".
She added that the tester had not been recalled, pending further investigations into the device.
The British Department of Health said a "hazard notice" had been issued following the fatality.
The incident comes as Medica is recovering from a crisis over faulty hip and knee implants in the United States. The company is facing hundreds of lawsuits from mainly elderly people who have had to undergo revision surgery to replace the implants.
Tschanz said the markets had punished Sulzer Medica's shares because of concerns about the US litigation. "It shows how nervous the markets are about the faulty hip and knee implants. From an image point of view, it hurts."
Sulzer Medica last month reported that it made a loss of SFr1.19 billion ($0.71 billion) in 2001, mainly because of the litigation in the US.
The company's management said then that it was confident that a settlement totalling almost $1 billion would be accepted at a final fairness hearing next week in Cleveland, Ohio.
Medica shares have more than doubled in value this year, as investors have started to return, but they remain well below the SFr400 level seen in early 2001.
swissinfo with agencies