Wessex Water and The Environment Agency have confirmed that sewage was discharged into the river Avon on Monday (31st October).
The leak happened following a blocked sewer burst.
Fortunately, the area affected had already been cleared of fish for the construction of the River Park project, and the pollution clear up began quickly.
The Environment Agency has had staff on site monitoring the clear-up work, which has meant a suspension of the River Park project work.
Salisbury's MP, John Glen, said in a tweet: "I am extremely disappointed by the news that sewage has made its way into the River Avon following a burst and blocked sewer. I urge @wessexwater to work with the @EnvAgency to act quickly in preventing the spill from further infecting our water ways."
There has been no confirmation about how long the delays to the River Park project will last. The project is being run by Wiltshire Council and The Environment Agency and is designed to help prevent future flooding in Salisbury.
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