STV has reported that work was halted at Easter Langlee in Galashiels, Selkirkshire, after scientists found both methane and carbon dioxide in borehole investigations in a section of the development.

A report with the findings was submitted to Scottish Borders Council and work on phase two of the development, which is beside a major landfill site, was stopped immediately.

High levels of carbon dioxide can cause drowsiness and headaches, and in extreme cases suffocation. Although methane isn’t toxic, it is highly flammable.

However there is still concern growing among residents who are already living in the 118 homes of the development which were completed in phase one.

Those houses were build four years ago with a further 396 properties being built by Persimmon Homes East Scotland in this second phase.

A council spokesman said: “A report was submitted to Scottish Borders Council earlier this year by the developer which indicated elevated levels of methane and carbon dioxide gas around the northern boundary of phase two of the site.

“The council’s environmental health officers issued a response to this report setting out their advice.

“The council has asked the developer to stop work on phase two of the site until a time when all suspensive planning conditions relating to the site are satisfied.

“No existing buildings need to be removed at this time.”

Persimmon have now submitted a report to the council with plans to reduce the risk of gas.

They have also requested permission to continue building on parts of the site which have not shown signs of gas.

Jim Kirkpatrick, managing director at Persimmon, added: “Persimmon Homes were recently required to provide the Scottish Borders council with a contamination report in order to pass suspensive planning conditions for phase two at Easter Langlee.

“This report highlighted elevated levels of natural gases, methane and carbon dioxide, around the northern boundary of the site. As a result we have been asked to provide another report which identifies the areas affected and details any mitigation work proposed to deal with this issue.

“This new report, which was prepared by our independent environmental consultant, was submitted to the council recently. We believe it confirms that a handful of properties along the northern boundary of the development will require a standard gas membrane. However, the vast majority of units, including those under construction in phase two, will be unaffected.

“We have agreed with the council to suspend construction work on the area in question until they are fully satisfied with a new report which allows them to sign off our suspensive planning conditions.”