More than one in 10 CCTV cameras used to spot motorists who have broken down on a smart motorway do not function properly, according to an investigation.

The Daily Mail reported that 112 cameras out of 804 were found to be broken, unusable or pointing away from the road.

It said this is based on analysis carried out on September 17 by a journalist working undercover for National Highways, formerly Highways England, at a regional control centre in South Mimms, Hertfordshire.

National Highways launched an inquiry into the allegations, but said that fatalities are less likely on smart motorways than on conventional roads.

Among the 112 cameras not functioning properly, according to the Daily Mail, were:

– Eight out of 19 cameras on the M25 between Junction 26 for Waltham Abbey and Junction 27 for Epping, both in Essex.

– Four out of 16 cameras at Junction 34 of the M1 near Sheffield, where there have been a spate of fatal crashes.

– Eight out of 59 cameras on the M5 between Junction 4a for Bromsgrove, Worcestershire and Junction 6 for Worcester.

The issue is putting drivers at risk by extending the time it takes for operators to close lanes and send help when someone has broken down in live traffic, according to the newspaper.

It alleged that the entire CCTV system in the control centre crashed several times during the six-week period the undercover journalist was there.

Outdated hardware such as CCTV boxes dating from 2004 add to delays helping drivers, it was reported.

All-lane running smart motorways involve converting the hard shoulder into a running lane.

This is a cheaper way of adding capacity compared with widening carriageways, but concerns have been raised about vehicles stopped in traffic being hit from behind.

There are about 375 miles of smart motorway in England, including 235 miles without a hard shoulder.

An additional 300 miles are scheduled to be opened by 2025.

Roads minister Baroness Vere told MPs in June that smart motorways have “many systems in there that make you safer” including “eyes in the sky” and sensors in the road.

Claire Mercer, whose husband Jason Mercer died on a stretch of the M1 without a hard shoulder, demanded that the rollout of smart motorways is immediately stopped.

Mr Mercer, 44, and Alexandru Murgeanu, 22, died near Sheffield when a lorry crashed into their vehicles which had stopped on a stretch of the M1 without a hard shoulder after a “minor shunt” in June 2019.

Mrs Mercer described the allegations of CCTV faults as “shocking and heartbreaking”.

She told the PA news agency: “I knew there were underhand tactics, I knew there were lies and deceit.

“But to see it laid out like that just breaks my heart again to see the lengths that they go into to just try and keep a cover on this.

“All they’re achieving is maiming and killing more people. They just need to stop now. They just need to accept it didn’t work.

“It cost billions and billions of pounds, it killed God knows how many people, and we just need to stop.”

National Highways chief executive Nick Harris insisted that smart motorways “work as a system, with technology, infrastructure and people working together”.

He continued: “Data shows fatalities are less likely than on conventional motorways.

“If there is a problem with any one part of the system, other parts are activated to help keep traffic moving safely.

“Our traffic officers work around the clock, every day of the year to help drivers and deal with incidents. We are, however, investigating these allegations as a matter of urgency.”

National Highways said it does not recognise the Daily Mail’s figures on the availability of CCTV.