Further concerns have been raised over the safety of a town's water after 400 fish have died and 'blue sludge' has been spotted.

Royal Wootton Bassett residents were left “horrified” on Wednesday, September 4, after multiple fish were spotted floating dead on the water at Jubilee Lake.

The concern sparked an emergency investigation by the Environment Agency and Wessex Water who visited the site several times to take samples from the lake, and walkers were urged to keep their dogs away from the lake.

But more than two weeks on, further concerns have been raised after 'foul-smelling blue sludge' was spotted at Thunderbrook in the town.

In a statement, Royal Wootton Bassett Town Council confirmed that approximately 400 fish lost their lives due to a drop in oxygen levels in the water at Jubilee Lake.

Although oxygen in the lake has now returned to an acceptable level, investigations are continuing to be carried out at Thunderbrook.

Foul-smelling and foaming 'sludge' has been spotted at ThunderbrookFoul-smelling and foaming 'sludge' has been spotted at Thunderbrook (Image: Public) "Last week we received more reports and complaints of the water in Thunderbrook, being a blue sludge and foam appearing from the car park pipe, and down the brook through the woods," said a spokesperson for Royal Wootton Bassett Town Council.

"All the information and images of the issues have been passed to the Environment Agency to ensure they are kept up to date with the situation.

"The Environment Agency (Fisheries) has confirmed they will not be returning to the site, unless there are further dead fish, and that the matter is now with the Environment Management Team.

"The Environment Management Team is now leading the investigation into the potential contamination of Thunderbrook, which is creating an odour through the wood to the lake."

Concerns first started over the death of 400 fish in Jubilee LakeConcerns first started over the death of 400 fish in Jubilee Lake (Image: Public) One resident who visited the area on Saturday, September 21, described noticing an "immediate smell of sewerage".

"Thunderbrook is flowing very strongly of black foul-smelling water foaming in places. It is like that all the way down the valley," said the resident.

Despite the ongoing investigation, no cause for the sudden loss of oxygen at Jubilee Lake or the foaming sludge at Thunderbrook has yet been confirmed.

The town council's ground team will now visit the Jubilee Lake/Thunderbrook site each day to continue closely monitoring the situation while Environment Agency investigations continue.