The “apparent failure” of the NHS contact-tracing app has “complicated” the effective operation of the government’s test and trace system, a new report found.

The report from the Independent SAGE, a group of 12 leading scientists headed by former UK Government chief scientific advisor, David King, said the governments test, track and trace system is not “fit for purpose”.

The government’s current approach to this system, including the contact-tracing app, is “severely constrained by lack of coordination, lack of trust, lack of evidence of utility and centralisation”, it adds.

The report also flags how the app’s importance has waned in recent weeks.

“The effective operation of this subsystem is also complicated by the apparent failure of the app that was designed to facilitate identification of contacts of those who have Covid-19,” it states.

“When it [the app] was planned, it was hailed by ministers as being essential. Now it is described as of marginal importance. Importantly, this is one of the many area where the UK went its own way, taking an approach that was very different from other countries.”

The Independent SAGE found the virus would only be contained if 80% of contact of infected people are traced.

The constraints highlighted will likely make achieving that goal “impossible”, they added.

The panel criticised the government’s decision to develop a centralised contact-tracing model which they say challenges public trust due concerns over “confidentiality and security of the data”.

“These concerns are especially the case for the smartphone app component of the system which uses Bluetooth technology to share data across phones and has been developed and will be implemented by a private provider,” the report found.

“There is a concern that there may be fraudulent use of the system given it is not being carried out by local, familiar and trusted services.”

Five key recommendations are made, including the flow of data within existing NHS, local authority and Public Health England data structures.

The future application of m-health systems, such as apps, must be implemented within such a framework that provides appropriate safeguarding and governance of data.

Sir David King said: “The government has placed huge emphasis on their test, track and trace system in recent weeks, even labelling it ‘world beating’. It is clear from our research that this simply isn’t the case, indeed the system as it stands is not fit for purpose.

“This is the critical moment for the government to act now or risk further spikes. We believe that a new approach is required, one that moves away from a centralised system that utilizes a local first approach.

“We are calling on the government to urgently rethink their course to ensure that we have a system in place that will help and not hinder the country’s recovery.”

The governments test and trace system was launched on 28 May without the contact-tracing app, despite the app being heralded as key part of the system for months prior.

A trial of the app was launched on the Isle of Wight on 4 May, with health secretary Matt Hancock and NHSX chief Matthew Gould both saying a national roll-out was expected by mid-May.

Prime Minister Boris Johnson later said the test and trace system, which was expected to include the app, would be live by June. No date has been provided for the apps roll-out.

The app, and wider contact-tracing approach, has faced fierce criticism from data protection and privacy experts, with the majority agreeing a centralised approach offers a greater risk of re-identification.

The Independent SAGE report highlights that the centralised system in England is “untested and being operated by companies with no experience in this area”.

The NHS’s own ethics advisory board, set up to oversee the development of the app, has warned unreliable apps could provide a false sense of security and increase the spread of the virus.

It raised concerns about the risk of false positives from an app relying solely on self-reporting of symptoms. Similar concerns have been raised by a number of other experts.

This week it was revealed data from the app could feed into the NHS Covid-19 data store, designed to aid the government’s future planning in response to the virus.