Poisonous chemicals have been discovered in the soil on part of a housing estate.

About 30 gardens in Wigston's Little Hill estate have been found to have quantities of potentially harmful toxins above recommended levels.

Homeowners have been served with a legal notice saying the land is contaminated.

Consultants have been brought in to look at how any potential health risks can be removed.

Oadby and Wigston Borough Council today stressed the health risks were very slight, but said it could not rule out the possibility that the levels of chemicals found might cause "significant possibility of significant harm".

Stephen Bruce, the council's head of environmental health, said: "There is a low risk but that doesn't mean there is no risk.

"There are possible health implications from long-term contact with this.

"We have asked residents if they have suffered any illnesses, they have not. We also have no records of any clusters of illnesses in that area."

Residents have been issued with advice which includes not letting children play with the soil, making sure soil is not brought into the house by leaving dirty shoes outside and not wearing soiled clothes indoors.

In 2006, 58 households in Salcombe Close, part of Pochins Close and a handful of homes in Launceston Road were warned they could be at risk of contamination because their homes were built on land which used to be Great Wigston Gasworks.

The gasworks, on the site for 100 years, extracted gas from coal – a process which left behind chemicals including coal tar derivatives and heavy metals such as lead.

Tests have found about 30 of the properties had higher than recommended levels of these chemicals in the soil. The borough council would not reveal which properties are affected.

Homes, roads and paths are not a risk as the chemicals remain locked in.

Experts said the main ways of tackling the problem were to inject chemicals into the soil to counteract the poisons or to dig out a deep layer of soil, put in a seal layer and add clean topsoil.

A council spokesman said the authority was pursuing all avenues for funding remedial works and was keeping residents fully informed.

One resident of Pochins Close said: "The council has been up-front, but it is clear it cannot make any promises about the risks or how quickly it will all be sorted."

Since 2000, councils have been required to identify sites which could pose an environmental risk under the Contaminated Land (England) Regulations.

Before that, there was no need for a developer to investigate whether a site was contaminated.