A 42-year-old man, Deepak Marawi, who had participated in the trial of Covaxin, the COVID-19 vaccine developed by Bharat Biotech, died nine days later in Bhopal, officials said.

While doctors suspect that poisoning could be the cause, Bharat Biotech said in a statement that “preliminary reviews” indicate that the death was unrelated to the vaccine trial.

Dr Rajesh Kapur, Vice-Chancellor, People’s Medical College and Hospital where the trial was conducted, told PTI that Deepak Marawi, the deceased, had participated in the Covaxin trial on December 12. He died nine days later.

Bharat Biotech said in a statement that Marawi had fulfilled “all the inclusion and exclusion criteria to be accepted as a participant in the Phase III trial”.

He was reported to be healthy in follow-up calls post seven days of his dosing and no adverse reaction was observed or reported, the Hyderabad-based company said.

“The volunteer passed away nine days after the dosing and preliminary reviews by the site indicate that the death is unrelated to the study dosing. We cannot confirm if the volunteer received the study vaccine or a placebo as the study is blinded,” it added.

Dr Ashok Sharma, Director, Madhya Pradesh Medico-Legal Institute said the doctor who performed autopsy suspected that he died of poisoning. However, the exact cause of the death would be known from his viscera test, he added.

“After Marawi’s death on December 21, we informed the Drug Controller General of India and Bharat Biotech, which is the producer and sponsor of the trial,” Dr Kapur said.

He said Marawi, a tribal labourer, had volunteered for the trial and was examined. “All protocols were followed and Marawi’s consent was taken before allowing him to participate,” he claimed. Dr Kapur too said he cannot confirm whether Marawi was administered the vaccine shot or was given a placebo.

“It (the vaccine vial) comes covered and coded. During the trial, 50 per cent people get the actual injection while the rest are given saline,” he said.

Kapur said Marawi was kept under observation for 30 minutes after the trial as per guidelines before he was allowed to go. “We monitored his health for seven to 8 days,” he added.

Family members of Marawi claimed that when he returned home, he felt uneasy and experienced some health problems.

“He complained of shoulder pain on December 17. Two days later, he frothed at the mouth. He refused to see a doctor saying he would be alright in a day or two. When his condition deteriorated, he was being rushed to hospital but he died midway (on December 21),” they added.

Rachana Dhingra, a Bhopal-based social activist, claimed neither Marawi’s consent was taken for participation in the clinical trial nor he was given any proof of his participation in the exercise. However, the hospital has denied this charge.

The Drugs Controller General of India (DCGI) last week approved Oxford COVID-19 vaccine Covishield, manufactured by the Serum Institute, and Covaxin of Bharat Biotech for restricted emergency use in the country.