About 10,000 fish have been killed by an agricultural pollutant, the Environment Agency have said.
An investigation revealed roach and trout died in the River Mole, South Molton.
The Environment Agency said the source of the chemical-based pollutant which impacted 5km (3.1 mile) of a river had been identified and it would now be working out how it got into the river.
The results of the investigation should be released later this week.
There is no longer a danger of the pollution killing any more wildlife in the river because the officers on site got as much pollution out of the river as possible, the Environment Agency said.
It is continuing to restore oxygen levels to the river to protect wildlife.
Courtesy of BBC News
Emergency services have been called to an Essex seafront after several reports of people coughing and struggling to breathe.
Members of the public began reporting the incident at the seafront off Fourth Avenue in Frinton just after 2pm on Sunday.
People on the beach said they had been left struggling to breathe and Essex Police advised people not to go into the sea while the cause is investigated.
It was speculated online that a fuel spill had occurred but the Maritime and Coastguard Agency said there was no immediate evidence after it sent a counter pollution aircraft to the scene.
Miriam Lansdell, who was visiting her parents in Essex, said: “My daughter started coughing. She said ‘I don’t feel good, it hurts to breathe in’. My other daughter was gasping and couldn’t form words because she couldn’t breathe well enough.”
The mental health worker, 45, said she also had problems breathing as she lay on the sand after taking a swim.
When they moved further away from the beach they all began to feel better but she took her 10-year-old girls to a clinic to be checked.
Her father had been told by someone in a speedboat that there may have been a fuel spill, Ms Lansdell said.
She said: “My dad said he had been asked to get out of the water by a man on a boat. He asked why and the man said there had been a fuel spill. He said if anyone is having breathing difficulties they should probably call an ambulance.
“It’s not what you expect when you go for a day out to the beach.”
One person tweeted that there were “lots of people coughing heavily”.
A mother said her son began coughing after swimming and had to be given his inhaler.
Another said: “We have just left Frinton and have seen lots of fire engines on the way out. Has there been an incident? We were on the beach and all developed a cough and were struggling to breathe.”
East of England Ambulance Service said people should wash themselves down if they were in the water, change their clothes and drink fresh water.
A spokeswoman added: “We are aware of an incident on Sunday 25 August with reports of a number of people suffering from coughing on the seafront off Fourth Avenue, Frinton.
“We are assisting the police and fire services with this incident. The cause is currently unknown.”
Anyone with further concerns is advised to call the NHS on 111.
Courtesy of Sky News