In Khartoum State, where the conflict in Sudan erupted last year, more than 61,000 people have been killed, according to a report by the London School of Hygiene and Tropical Medicine's Sudan Research Group.
Deaths in war-torn Sudan significantly higher than previous tolls, according to new report
The UN and other aid agencies had previously reported 20,000 confirmed fatalities.
Due to the disorder in the country, there has been no system to record the exact number of deaths.
Among the fatalities, 26,000 were the result of direct violence, the report states.
The main causes of death across the country, meanwhile, are starvation and preventable disease.
According to aid groups, the fighting has triggered the world’s worst humanitarian crisis, with multiple areas facing the threat of famine.
After visiting the country in September, the head of the World Health organisation reported that starvation was 'almost everywhere'.
Both of the warring sides, the Sudanese army and the paramilitary Rapid Support Forces have been accused of committing war crimes.
More than 11 million people have been displaced by the fighting, which broke out in April last year.