A major incident has been declared after about 200 barrels of reservoir fluid including oil leaked into the water at Poole Harbour in Dorset.
Poole Harbour Commissioners (PHC) said a leak occurred at a pipeline operated by Perenco, under Owers Bay yesterday.
Members of the public have been urged not to swim at Poole Harbour or the surrounding area until further notice.
Perenco said a “full investigation” would be carried out into what had happened.
Poole is the largest natural harbour in Europe and a Site of Special Scientific Interest (SSI) which is home to a range of wading birds.
In a statement PHC said: “It is estimated that approximately 200 barrels of reservoir fluid has been released into the water column in Poole Harbour.
“Anyone who has come into contact with the spill should wash immediately with soap and water. If eyes have come into contact with the spill, they should be rinsed with water.”
It added it had activated its oil spill plan and the pipeline had been shut down, with booms placed on either side of the leak.
Companies specialising in oil spill response have also been mobilised, according to PHC.
Perenco said its incident management team had been activated immediately to stop the leak and a clean-up operation was underway.
Franck Dy, Perenco UK’s Wytch Farm general manager, said: “Any spill is an extremely serious matter and a full investigation will be launched to ascertain what happened in Poole Harbour.
“It is important to stress that the situation is under control, with the discharge of fluids having been stopped and the spill is being contained.”
Bournemouth Christchurch and Poole Council, said it was “working as part of a multi-agency response to the major incident declared this afternoon”.
In a statement on Twitter, council leader Philip Broadhead, added the leak had been declared as a major incident so that “all relevant partner agencies (were) working together”.
Yesterday afternoon, the Environment Agency said it had received reports of a “large amount of oil” in Poole Harbour.
“We are supporting the port authority and other partners in responding to this incident.”