(CNN) -- Preliminary tests on a suspected source of the cholera outbreak in Haiti were negative, U.N. peacekeepers said Thursday.
The U.N. mission in Haiti is testing waste and sewage water at the back of a Nepalese military base that is part of the U.N. operations. The first tests showed no signs of cholera, officials said.
The mission said it "has taken very seriously the allegations that sewage water coming from latrines at the back of the Nepalese military base in Mirebalais could be the source of the cholera outbreak in Haiti."
U.N. workers took the initial samples last week from the camp and an adjacent river. Additional samples were taken this week and results are expected by Friday.
The death toll from the cholera outbreak has risen to 305, and the number of confirmed cholera cases has reached 4,649, the Haitian government said Thursday.
Suspicions about the Nepalese base arose from reports that water was collecting at the back of the base. It was believed to be overflow from the latrine or a septic tank.
U.N. engineers examined the base and concluded that the standing water was not from the latrine of septic tank, but from a soak pit that receives water from the kitchen and the shower area, the U.N mission said.
"This soak pit is located three meters from the latrines, hence misleading passers-by into believing that the soaked ground close to latrines is caused by the overspill of human waste," it said.
All human waste from the camp is collected in seven septic tanks that are emptied out and discharged in a local landfill as authorized by the local government, the United Nations said.
The agency also noted that all 710 Nepalese soldiers underwent medical tests, and tested negative for cholera, before deployment to Haiti earlier this month.