The Government has admitted paying social media influencers and reality TV stars to promote its NHS Test and Trace system.
After failing to reach its 80 per cent target for the ninth week in a row, a spokesman said the Government had a responsibility to "use every means possible" to keep the public informed during the coronavirus pandemic.
"Our use of social media influencers has meant over 7 million people have been reached," he said.
"This is just one part of a wider campaign utilising TV, radio, social, print and other advertisements to ensure the public has the information it needs."
It comes as the Sunday Mirror reported Love Island stars Shaughna Phillips, Chris Hughes and Josh Denzel were among those paid by the Cabinet Office to tell their online followers testing for Covid-19 was "free, quick and vital to stop the spread".
Phillips and Hughes have also both posted images online in the last month which showed them failing to socially distance from others on Mediterranean islands.
The Mirror quoted a social media expert as saying the stars would usually command between £5,000 and £10,000 for an ad post.
The Government’s spokesman said: "All costs involved in the campaign will be published as part of the regular transparency reports on gov.uk."
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The celebrities could also face an investigation by the Advertising Standards Agency after not initially labelling their posts as advertisements.
The Government’s spokesman indicated the Cabinet Office had been clear about labelling such content correctly and noted all three posts had "now" been marked as ads.
Data showed three-quarters of close contacts of people who tested positive for Covid-19 were reached through the Test and Trace system, once again falling short of the Government’s target.
Some 75.5 per cent of close contacts in England were reached in the week ending August 19.
While this is up from 71.6 per cent in the previous week, it is the ninth week in a row where the Government’s Scientific Advisory Group for Emergencies (Sage) target of isolating 80 per cent of contacts of coronavirus cases within 48-72 hours has been missed.
Ahead of the figures being published, Health Secretary Matt Hancock acknowledged the system was "not quite there".