(CNN) -- The FBI said Friday that it is now assisting in the investigation into the death an accomplished Pittsburgh doctor who, local authorities say, might have died from cyanide poisoning.
Autumn Klein, 41, who was a physician and former head of women's neurology at the University of Pittsburgh Medical Center, died on April 20. Her husband called 911 after finding her at home, according to Mike Manko, communications director for the Allegheny County district attorney's office.
Klein's death is being investigated as a potential homicide or suicide, said Manko.
While it will take a few weeks for tests to be complete, it is suspected that toxic levels of cyanide were found in her body during an autopsy, according to Dr. Karl Williams, Allegheny County, Pennsylvania, Medical Examiner.
"I do not believe this could have been an accident. The death of this 41-year old physician is highly suspicious," said Rick Lorah, forensic supervisor for the Allegheny County medical examiner.
The hospital where Klein worked did have cyanide among its supplies, and she or someone she worked with would have had access to it, according to Lorah.
Cyanide is a naturally occurring toxic substance that can be found in seeds of different plants. It is widely distributed throughout research laboratories as a chemical used in scientific experiments, Williams told CNN.
Cyanide interferes with the ability of the body to use oxygen to produce energy, which can lead to rapid death in humans, according to Williams.
Despite its availability in laboratory and other settings, cyanide-related deaths are very rare, Williams said. He added that in 35 years as a forensic pathologist and in seven years of working as the Allegheny County medical examiner, he has never seen or dealt with a case directly involving a potential cyanide homicide or suicide.
A search warrant was executed for the lab at the University of Pittsburgh's School of Medicine where Klein's husband, Robert Ferrante, works, according to Manko.
Calls to Ferrante were not returned Friday.
The Allegheny County district attorney's office and the Pittsburgh police department's major crimes division are heading the investigation.
Kelly Kochamba, spokeswoman for the FBI in Pittsburgh said, "We're assisting the Pittsburgh Police with the investigation." No further details were given.