Visitors to a popular beach in north Wales were left horrified when the sea turned brown over the Bank Holiday weekend.

The cloudy waters at Porthdinllaen in Gwynedd raised alarm bells over the Bank Holiday weekend, with locals fearing a sewage leak had taken place. However, Natural Resources Wales has addressed public concerns and since clarified that no such incident occurred, revealing that the discolouration stemmed from naturally occurring algae. Arfon Hughes, environment team leader for NRW, said: "Our officers received reports of potential pollution at Porthdinllaen beach over the Bank Holiday weekend. Upon inspection, this was found to be a type of non-toxic algae called Phaeocystis – one of the most common bloom-forming algae in our coastal waters.

"The blooms can form a brown, frothy scum that is harmless and may be influenced by recent sunlight and warmer temperatures," reports North Wales Live.

"Anyone with concerns about potential pollution can report them to us by calling our 24/7 incident communication line on 0300 065 3000 or by using our online incident form."

The picturesque Porthdinllaen boasts an expansive sandy shoreline protected by the Carreg Ddu headland. The area has escaped major development, and parts are now owned by the National Trust.

It is famed for its beach pub, Ty Coch, which has been named among the best beach bars in the world.

It was named one of the next beaches in north Wales to visit this summer by North Wales Live, though in the summer it can get busy with visitors.

Getting there requires some effort – either a trudge along the sand from the National Trust car park in Morfa Nefyn (free for members), or a hike across Nefyn golf course if you pay for parking near the clubhouse.