HEALTH chiefs have launched an investigation and warned against swimming at a well-known beauty spot ­– after several teenagers fell ill after going in the water.

Lancashire County Council and the Environment Agency are looking into ‘a potential issue’ with the water at Rishton Paper Mill.

One schoolboy ended up in hospital and others suffered from sickness, diarrhoea and marks on their skin.

On Saturday, a week after the incident, Public Health England North West and Hyndburn Council said: “We have reports of children becoming ill after swimming in the water and would advise people not to enter the water.

“If you have been in this water and develop sickness or diarrhoea, fever or abdominal pain within 10 days of swimming contact your GP.”

The warning came as Great Harwood mum Jo Smith spoke out about her son Billy falling ill.

The teenager fell ill just over a week ago ­– on Sunday night – and was taken to hospital as he could not eat or drink on the Monday.

All of the friends have since been sick and had diarrhoea and have also had marks on their skin.

Speaking to the Lancashire Telegraph, Jo added that she has been worried sick about the Accrington Academy pupil.

She said: “All the kids go in the water and even I used to do it.

“It is pretty dirty and it has been called the River Stink at times.

“Billy said it was a bit murky and then he told us on Sunday that he felt sick but I thought he had been out quite a bit and may have picked up a bug.

“He was being sick and could not drink or eat. In hospital they gave him a fluid challenge where they gave him a small amount of of fluid – but he could not even have half without being sick.

“They put him on an IV drip and he is doing better now. He still has to visit the toilet and I have been told by the doctors if it continues he may still have to go in to hospital again.

“But the three including Billy who went in the water have been sick and had to go to the doctors.”

The mother said her son was “lifeless and rolling his eyes all over the place”.

She added: “It could have been so much worse if they could not have found out what was wrong.

“Children are children and teenagers are teenagers and they will go in the water if they want to but if we can tell the parents and young people about what the consequences could be then we can try to stop people getting ill.

“I’ve told Billy many a time that you just don’t know what is underneath you at places like this.”