The Enquirer understands that urgent tests are being carried-out on segments erected on the 2.5km Chipping Warden Green Tunnel where work started earlier this year.
Site sources said the part-erected tunnel may have to be demolished depending on the extent of the issues.
The tunnel segments are being made by Stanton Precast in Ilkeston Derbyshire for main contractor EKFB – a team made up of Eiffage, Kier, Ferrovial Construction and BAM Nuttall.
The Chipping Warden Green Tunnel will eventually consist of more than five thousand concrete tunnel segments before being covered by earth, with trees, shrubs and hedgerows planted to fit in with the surrounding countryside.
All 5,020 segments will be steel reinforced, with the largest weighing up to 43 tonnes.
Chipping Warden is one of a series of green tunnels planned on phase one of the HS2 project.
An HS2 spokesperson said: “Chipping Warden is the first of three green tunnels made of precast segments and it’s important that we take the time to get the quality assurance and installation process right.
“We have recently identified quality issues with some of the segments and we are currently conducting tests to determine whether remedial work is needed.
“No decision has been made yet and we are actively engaging with our supply chain partners to resolve the problem.”
