Speaking to BBC Breakfast on Friday, former Det Sup Blaik, who led the Thames Valley Police investigation, pointed to remarks by the judge who sentenced PC Harper's killers. Mr Justice Edis referred to their case of manslaughter as being "very close to a case of murder in its seriousness".

The former officer called for prisoners who were judged to have had a high level of culpability for a manslaughter offence to be excluded from the scheme.

Allowing them to walk free would "undermine" the judicial process and impact police morale, Blaik said, before urging the government to have a "long, hard think" about the case.

The former Det Sup left Thames Valley Police in 2023. This is the first time he has publicly shared his views on the issue.

In an earlier statement given exclusively to BBC Breakfast, he said "like many people across the country" he was "deeply concerned and appalled" by the prospect of Bowers and Cole being considered for early release.

He said that because the "death of Andrew was such a serious and tragic case", Bowers and Coles should "not be afforded the opportunity" to be released early.

"Neither of them showed any remorse during their time in police custody or during their subsequent trial.

"I hope the Government takes account of the strength of public feeling on this issue, which has been both clear and widespread," he added.

Under revised plans announced by the government on Monday, prisoners who have committed rape, grooming, and serious child sex offences will be excluded from an early release scheme for England and Wales.

But those guilty of manslaughter may still be eligible.

Bowers and Cole were sentenced to 13 years for the manslaughter of PC Harper.

They will become eligible for release from prison after serving half of their sentences under the plans, instead of two-thirds.

The driver of the getaway car, Henry Long, was jailed for 16 years for the same offence. But Long will not be eligible.