A nurse of Mymensingh Medical College Hospital (MMCH) died on early Thursday with symptoms of the novel coronavirus.
The deceased was identified as Shefali Das, 55.
Dr ABM Mashiul Alam, civil surgeon of the district, confirmed the matter to The Business Standard.
"She had been suffering from breathing difficulties and tested positive for Covid-19 on April 24. But she went for the coronavirus test on the 8th and the 13th of this month and her results came out negative in both occasions," he said.
"We have collected samples from the dead body to know if she really has died of Covid-19," added the Mymensingh civil surgeon.
Meanwhile, family sources of Shefali Das said that she feet ill all of a sudden and was taken to the MMCH where doctors declared her dead.
"My mother was sweating and she had breathing shortness. She started becoming lifeless in the following few moments," said Ardita Dev Tithi, daughter of Shefali Das.
Dr Laxmi Narayan, deputy director of the MMCH, said Shefali tested Covid-19 positive while serving in the hospital.
"Later, she took a break, and resumed duty after recovering from the illness. She also had several tests and results of all those came out negative," he added.