Sewage flowing into the sea at a once-popular swimming spot is forming puddles on the rocks and causing a "nauseating stench". 

The situation has been ongoing for more than a week, residents say, with authorities doing little more than warning people not to swim there.

A photograph sent to Times of Malta shows the sewage forming green puddles on the beach as residents claim black water is flowing into the sea.

Sliema Mayor John Pillow has also pleaded to the authorities to stop the sewage outflow in Qui-si-sana and return the bay to the people.

"We cannot continue to have this outflow and resultant stench," he said."And we cannot continue to have a situation where everyone is blaming everybody else."

He said the Environmental Health Directorate was "pointing fingers at" the Water Services Corporation, and vice versa. 

Both authorities visited the area last week and the Water Services Corporation added colour to nearby sewage pipes to see if they could ascertain where the leak is coming from, he confirmed. 

He said in a Facebook video that the situation was shameful and needed to be tackled immediately.

The Environmental Health authorities issued a warning against swimming in the area a week ago and signs have been posted on the rocks along the beach. 

A resident of the area said it has been ongoing for at least 10 days. 

"Sewer waters are pouring into the sea where people bathe and these waters are also forming puddles on the rock," said Pietro Ferraglia.

He described the small as a "nauseating stench".

"The situation is unacceptable, the municipality is not taking action, it has just put up a sign saying that bathing is not recommended.

"But people, including children, continue to play near the sewer water and bathe in the sea where the black waters pour."