The RSPCA has issued urgent advice to the public about what to do if they see a struggling seal on a beach - after "well-meaning" members of the public returned one to waters in Pembrokeshire.

RSPCA Cymru’s plea follows the rescue of the moulted grey seal pup from Castlemartin beach, Pembroke on Wednesday, September 25.

The rescue of the seal was completed by Welsh Marine Life Rescue (WMLR). It is understood the pup was one they had earlier sought to rescue at Freshwater West; only for it to have been returned to the sea by members of the public before professional rescuers were able to reach the animal. The pup later then washed up at Castlemartin.

The seal is now in the care of the RSPCA and is receiving urgent rehabilitation and care at the RSPCA West Hatch Wildlife Centre in Somerset. However, a “long period of recovery” is ahead as the pup is in very poor body condition and is struggling with a bad infection.

She is also dangerously underweight – weighing only 11kg, when a pup of her age should be hitting the scales at between 30kg and 50kg.

The RSPCA has urged members of the public not to chase or move seals found on the beach into the water – as it is highly likely they have "headed to the beach for a reason” and are in need of help.

Ideally, lone seal pups looking fit and healthy should be monitored from a safe distance for 24 hours. If a seal pup is injured or in distress, the RSPCA's 24-hour emergency line should be contacted on 0300 1234 999.

RSPCA animal collection officer Ellie West said: “Many well-meaning people think they are helping lone pups by moving them into the water – but nothing could be further from the truth. They have usually headed to the beach for a reason, and are often in desperate need of veterinary care or support.

“It's not unusual to see a seal pup by itself, as their mothers will leave the pups alone very early on in life. If you find a seal pup that looks fit and healthy and shows no signs of distress, monitor it first from a safe distance for 24 hours.

“However, if the mother doesn’t return after 24 hours or the pup appears distressed, injured or unwell, or is on a busy public beach, our 24-hour emergency line can be reached on 0300 1234 999. Please always stay at a safe distance and keep dogs well away - seals can have a very nasty bite.”

For more information visit the RSPCA’s website.