The authorities on Friday recommended against swimming in the Font Għadir area of Sliema.
The Environmental Health Directorate said that, According to the Bathing Water Directive, it "wishes to notify that until further notice bathing is not recommended due to contaminated water percolating from a storm water culvert that effected the bathing water quality and that may represent a risk to bathers' health."
Environmental Health Officers are investigating to determine the source of contamination, it said.
The duration of the contamination cannot be predicted at this stage.
"Signs indicating the area have been fixed in the area. When the quality is restored, the signs will be removed, and another press release will be issued to notify the public that the site is again fit for bathing."
For further information, the public is kindly requested to contact the Environmental Health Directorate between 8:00 a.m. and 2:30 p.m. on telephone number 21337333 or by email on [email protected].