Just over two weeks since the transport secretary visited a new link road, it has emerged it may have to be ripped up and relaid.

Norfolk County Council said it had identified an issue with asphalt used by contractor Tarmac in the top layer of road surfacing used at a number of sites.

Patrick McLoughlin, secretary of state for transport, visited the A12/A143 link road on Thursday, March 3 on a visit to Norfolk.

At the time Mr McLoughlin said: “It is about time the people in Norfolk benefit from a road network fit for the 21st century and that is exactly what the government is delivering.”

A spokesman for the Department for Transport said that a lot of money had been invested in the region, including significant funds for the link road.

They added that the road-building project was led by the local authorities.

The new link between the A12 and the A143 south of the Yarmouth received £4.8 million from the Department for Transport and opened in December.

Staff at Tarmac discovered a problem with material produced by its Ipswich plant.

A total of 28 roadworks projects around Norfolk have been investigated, and problems have been identified at eight sites, including four in the Great Yarmouth area.

The other locations where the material was used will have to be monitored, to check it does not fail.

Tarmac will cover the costs of carrying out the remedial work – as it did in Norwich – but it is not yet clear when or what will need to be done.

The firm is still investigating the exact cause, which does not seem to be a uniform problem across all sites. It has brought in a specialist to help to resolve the issue.

David Allfrey, the county council’s highway and major projects manager, said the extent and timings of the work would be agreed with the council.

He said: “All works will be planned to ensure there is minimal disruption to the travelling public and all costs associated with the work will be carried by Tarmac. Whilst this is a very unfortunate incident, it is to Tarmac’s credit that they have acted swiftly to correct the immediate failures and also to accept the cost of dealing with the sites affected.

“There is still further work and monitoring to undertake and Tarmac’s investigations still need to be concluded, but the county council is reassured that the right approach has been adopted to deal with this.”

A spokeswoman for Tarmac said: “We’re working closely with the council to rectify issues and will be replacing affected material laid by Tarmac, in a way that minimises disruption to road users.

“We are extremely disappointed as this doesn’t reflect our usual high standards. We sincerely regret any inconvenience caused to our clients and the public.”

She said she was not able to disclose details of what it was costing Tarmac to redo the work.