FLY tippers caused a scare when they dumped more than 20 bags of grey powder into a stream on the outskirts of Bolton.

The white sacks were twice the size of a carrier bag, filled with an unknown grey powder.

A shocked 63-year-old passer-by spotted the bags and immediately contacted police and United Utilities officials.

An inspector attempted to pull many of the heavy bags from the stream which leads into Turton and Entwistle reservoir, off Greens Arms Road.

Tests later showed they contained a compost used for growing new plants.

But although the water company said the contents were non-poisonous and did not pose a risk, it has highlighted the problem of fly-tipping on its sites across the borough.

A spokesman said: "We have had many instances of items being dumped illegally on our land and it is something we are striving to tackle.

"In this case there was no threat to public health. If there had been, we would have taken every possible measure to rectify it."

The bags are now stored at Darwen police station. A spokesman said they would eventually be destroyed.

The passer-by, who does not want to be identified, said: "My face dropped when I saw these giant bags. I don't know how long they had been there but they were open and their contents were spilling out.

"It took me a while to get somebody out to inspect it. It could have been anything. For all anybody knew, these bags could have been poisonous and after the events of September 11 you don't dismiss anything."

There was no danger to wildlife in the area, the United Utilities spokesman added.