TikTok has removed a number of viral videos that showed school children how to fake a positive lateral flow test in order to stay away from the classroom after they were viewed by more than six million people.

The clips, which appeared to have been filmed in the UK, showed teenagers applying liquids to lateral flow tests in an attempt to force a positive result.

Suggestions for liquids that could be used included soft drinks and fruit.

The Telegraph’s Campaign for Children is urging ministers to reconsider its current policy of twice-weekly lateral flow testing for school children.

Professor Jon Deeks, an expert in biostatistics at University of Birmingham, said children had feigned illness to get out of school “since the dawn of time”.

“It really doesn’t take very much to game the system if you wanted to,” he said. “The system as it is is built around trust, and if there isn’t trust then it doesn’t go very far.”

Professor Sir Andrew Pollard, who led the Oxford vaccine programme, is among scientists to have questioned the purpose of lateral flow tests in schools.

“If children aren’t very much affected, then the testing is obviously not protecting them as they’re not very affected,” he said.

TikTok told The Telegraph they removed the offending content from the social network after its safety team found it violated its policy around misinformation.

“Our community guidelines make clear that we remove content which includes misleading information that causes harm to people on TikTok or the wider public,” a spokesman said.

“This includes medical misinformation related to Covid-19, and anti-vaccine disinformation more broadly. This trend violates our Community Guidelines and we are removing this content.”

As of Friday the trending hashtag #fakecovidtest – which had accumulated more than 6.5 million views – had been removed by the social media site, as well as a dedicated account called @.fakecovidtest.

In their place was a message which read: “This phrase may be associated with behaviour or content that violates our guidelines. Promoting a safe and positive experience is TikTok’s top priority.”

More than 50 million lateral flow tests have been administered in schools since they reopened in March, although as many as 60 per cent of “positive” tests per week have come back negative when checked against the gold-standard PCR tests.

The Telegraph carried out an experiment to discern whether the use of everyday substances on lateral flow tests was an urban myth or genuinely produced a positive result.

This newspaper found that in some instances a positive result was returned within the space of 15 minutes on NHS-standard lateral flow tests.

Campaign for children (Day 4)

“We would urge parents to ensure that tests are not being misused,” Geoff Barton, the general secretary of the Association of School and College Leaders, told the i newspaper.

“We would suggest to pupils who are interested in chemical reactions that the best place to learn about them is in chemistry lessons in school.”

The Department for Health was contacted for comment.