Two Dutch doctors flown home from west Africa after fears they might have been contaminated with the killer Ebola virus have left hospital "in good health," their employer, the Lion Heart Medical Centre, said Monday.

But the pair, Erdi Huizenga and Nick Zwinkels, have put themselves into voluntary quarantine for another two weeks at an unspecified location in the Netherlands as a precaution, it added in a statement on its Facebook page.

"They don't want to pose any risk for those around them and think that it would be best to not yet return to their homes," the charity said.

Huizenga, 39, and Zwinkels, 31, were on Sunday repatriated from Sierra Leone, where they had been working in a clinic their charity runs in the western town of Yele.

They were not presenting any symptoms of Ebola, a virus which has killed more than 2,400 people in west Africa so far this year in an epidemic international organisations said was running out of control.

But Zwinkels recently told Dutch state television that he and Huizenga has come into contact with Ebola-infected patients in the Sierra Leone clinic, which mostly treats malaria cases, and were "very concerned" because one other staff member in the hospital had died of the virus.

Several Western health workers have been flown home after being contaminated and given experimental drugs to combat the disease. Most have recovered.

The Ebola outbreak ravaging west Africa has killed more than 2,400 people since it erupted earlier this year, according to the World Health Organization.

Sierra Leone, Guinea and Liberia are the hardest-hit countries.

Although no vaccine is commercially available, early treatment involving constant rehydration and medication to alleviate fever increases the chances of survival.