A Spanish pathologist who specialized in a human strain of mad cow disease died Saturday, and officials suspect the disease played a role in his death, officials said.

The doctor was head of the anatomy pathology section at the University Hospital Principe de Asturias in Alcala de Henares, outside of Madrid, according to the Madrid regional government’s health office. He died Saturday night, at the hospital where he worked, officials said. The doctor’s name was not released at the request of his family.

Several samples have been sent off for testing, the office said, but results are expected to take a month.

The doctor was well known both in and outside Spain for his work in the pathology field. His speciality was the human strain of Creutzfeldt-Jakob disease.

It is not known how the doctor might have contracted the disease, but the health office said it was not thought to be through ingestion of contaminated meat. Authorities are investigating whether the doctor had been exposed to contaminated human tissue through his work.

Since 2001, 702 Creutzfeldt-Jakob cases have been reported in Spain, of which 87 have been reported in Madrid. Five people have died.