Spit hoods do not offer “effective” protection from coronavirus for officers from those threatening to infect them, their manufactures have said.

Amnesty International has urged the Police Federation to retract a recommendation that every officer should carry the hoods and suspend rollout.

The mesh and plastic guards do not stop droplets from coughing or sneezing, according to the leading manufacturer.

The Police Federation has called for the equipment to be introduced amid reports of officers being intentionally coughed at by people who said they had coronavirus.

In April, a representative of the Federation told the Home Affairs Select Committee that spit hoods should be rolled out to protect officers and they were subsequently endorsed.

The Spit Guard Pro is the model most widely used.

In March, the Police Service of Northern Ireland said it would deploy the equipment in custody suites where it questions suspects, but has since told Amnesty that the manufactures explicitly declared they provide no protection against COVID-19 spread.

Oliver Feeley-Sprague, Amnesty International UK's policing expert, said: "Spitting and threats to infect people are abhorrent, but spit hoods are not personal protective equipment and could put officers in greater peril."

Mr Feeley-Sprague went on to say: "This new admission from the manufacturers that the devices will not stop the spread of this deadly virus is startling, especially for any police officers who might have previously been under the impression that these devices would help keep them safe.

"The pandemic has been used as cover to roll out these controversial constraint devices, but we would urge police commissioners and chief constables to look again at the dangers posed to everyone involved.

"Spit hoods could actually be seen as an un-safety device and police chiefs should make it crystal clear to all their officers spit hoods do not offer any protection from Covid-19 transmission or infection.

He forces across the UK should now withdraw them from use in possible or suspected cases of COVID-19.

Simon Kempton is the operational lead for COVID-19 for the Police Federation.

He said: "COVID-19 is not only transmitted via aerosol means, through the air, but by contact with contaminated surfaces. And the spit guards help to prevent the saliva, phlegm or other bodily fluids being weaponised and contaminating surfaces.

"This protects not just officers, but the wider public we serve. And actually, as important it is for all of us to be mindful of COVID-19, my colleagues face contact with many other communicable diseases when subjected to a spitting or biting assault."

Chief Superintendent Sam Donaldson, from the force's Operational Support Department, said: "The PSNI has issued spit and bite guards as a temporary measure for use during the Covid-19 pandemic.

"We will continue to review this position in light of all available information."