The German International School Dubai has been closed since Sunday after a "possible contamination of water" was discovered.
The school halted lessons as a "precaution" and is working with the UAE authorities over the issue, said a statement issued on its behalf by the German Consulate.
Dubai Municipality has refuted reports of a Legionnaires’ Disease outbreak at the premises and the school is expected to reopen as normal on Tuesday.
"The German International School Dubai places highest priority on the health and safety of its community," said a statement issued by the German Consulate.
"Therefore, after a possible contamination of water was discovered, the school has been closed as a matter of precaution.
Redha Salman, director of the Health and Safety Department at Dubai Municipality, said there had not been any cases of Legionnaires’ Disease in any school in the emirate.
"There is no Legionnaires’ Disease in any School and we are not aware of such existence," he said.
Mr Salman said the school had "decided to conduct cleanup and maintenance of the tanks and piping in the school" when concerns were raised.
The illness develops within two to 10 days of exposure to the bacteria that causes it.
Common symptoms include headaches, muscle pain and a high fever.