Southern Water says plastic beads that washed up at Camber Sands over the weekend are believed to have come from its Eastbourne Wastewater Treatment Works.
The company says a failure in a screening filter during heavy rainfall allowed the small beads, used in the treatment process, to escape into the sea.
Southern Water has apologised and says it’s working to resolve the issue.
A spokesman for Southern Water said: "After completing the initial stages of a thorough investigation, which is continuing, we believe it is highly likely that the beads have come from our Eastbourne Wastewater Treatment Works. We've identified a failure of a screening filter which has apparently led to beads used in the treatment process being released into the sea during heavy rainfall. The screen should have prevented this occurring.

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