SEWAGE from household toilets may have contaminated the water of the region's best known park lakes.

Signs have been erected at Stewart Park in Middlesbrough warning that people and pets should avoid entering the water in the two lakes.

It is thought that nearby properties in the area have wrongly been plumbed to what should be a sewer network for surface water which enters the Stewart Park lakes.

A notice in the park reads: “We apologise for the current condition of our lakes. This has been reported to both Northumbrian Water and the Environment Agency who are investigating the cause.

“Please do not all any person or animals to enter the lakes.”

Northumbrian Water is the lead organisation in dealing with the problem although both Middlebrough Borough Council and The Environment Agency are also involved.

A spokeswoman for Northumbrian Water said: "We believe that some properties in the area may have wrongly plumbed their domestic appliances, toilets, baths or sinks into the surface water sewer network which enters the lake at Stewart Park.

"We are working closely with Middlesbrough Council and the Environment Agency to investigate.

"Extensive survey work is necessary to identify wrongly connected pipes and we will then work with customers to ensure faults are rectified as soon as possible. Everyone can play a part in protecting our environment by checking connections are correct."

A spokeswoman for the Environment Agency said: "We can confirm that Northumbrian Water has made us aware of this issue and it is for them to identify the cause. However we are monitoring the situation and have an overview."

A spokesman for Middlesbrough council said: "We are investigating the causes and continue to work with Northumbrian Water to ensure it is resolved."

There are two lakes at the 120 acre park which has a variety of water fowl. A fountain at the park was reopened last summer after the water system was stripped and cleaned after it had become clogged with rubbish and soil.

The park is the site of where Captain Cook was born in the 18th Century. The park was once the grounds of a now-demolished grand house built by Henry Bolckow, one of the industrial founding fathers of Middlesbrough. It was bought by Thomas Dorman Stewart in 1924 and gifted to the people of the town.