Signs warning sea bathers about the water quality have been put up on beaches across North Down, and are predicted to be in place until further water samples can be taken and analysed.

Ms Egan has said: “Whilst it’s reassuring that we have the mechanisms in place to regularly test for water quality and the safeguards to protect people from harm, this is incredibly concerning.

“We’re so lucky in North Down to have the natural resources that we do, with so many beautiful beaches both locals and visitors alike make use of for activities like sea swimming, kayaking, and paddle boarding, among many others. It’s a real shame to see any of them out of action for any length of time, but for a number to be affected at once is very worrying indeed.

“I welcome the news that DAERA have launched a water pollution investigation, and I will be following up with them as well as the NI Environment Agency soon in order to gain some much-needed clarity around what has happened here.

“However, in the meantime I’d urge everyone to heed official advice and stay out of the water at these spots until it’s deemed safe.”