Doctor Sheik Umar Khan died on Tuesday, Sierra Leone's chief medical officer, Brima Kargbo, told Reuters. He had treated more than 100 patients infected with the virus.
Doctor Sheik Umar Khan, who has been leading the fight against Ebola in Sierra Leone, has tested positive for the deadly virus and is now being treated in a hospital, BBC reports.
In West Africa alone more than 630 people have died of Ebola since the outbreak began in Guinea in February, according to the World Health Organization.
It is the world's deadliest outbreak of the virus yet. There is currently no cure for Ebola. The virus, which spreads through contact with an infected person's bodily fluids, kills up to 90% of those infected.
Sierra Leone's health minister called Dr. Khan a "national hero," and said she would "do anything and everything in my power to ensure he survives."
In late June, the 39-year-old doctor spoke with Reuters and said he was worried about contracting the virus. "I am afraid for my life, I must say, because I cherish my life."
"Health workers are prone to the disease because we are the first port of call for somebody who is sickened by disease," said Khan. "Even with the full protective clothing you put on, you are at risk."
The government statement said that the minister of health was in tears when she heard that Khan was infected.
On Monday, three nurses at the government hospital in the town of Kenema, where Khan also worked, died from Ebola. Dozens went on strike following the deaths, but have since returned to work as the government has agreed to look into their demands to relocate the Ebola ward from the hospital.