SCOTLAND's green ­watchdog is investigating warnings that construction waste may be being dumped under the upgraded M8 and M73 motorways outside Glasgow.

The Scottish Environment Protection Agency (Sepa) said it was currently in talks with contractors - the Scottish Roads Partnership joint venture - carrying out the project to see if work was in line with laws designed to prevent avoidance of landfill tax.

A spokesman said: "We have been investigating a complaint made regarding a deposit of waste, to form temporary roads at Aitkenhead Road, Uddingston, associated with the M73/ M8 upgrade works.

"We are currently in discussion with the operator and assessing whether a breach of environmental legislation has occurred."

Transport Scotland, who commissioned the work, said it believed all materials supplied complied with Sepa guidelines.

It said: "As part of the M8/M73/M74 Motorway Improvements Project, Scottish Roads Partnership has a contractual requirement to maximise the re-use of materials and prevent unnecessary production of waste. SRP is using recycled aggregate and road planings as an engineering fill."