A head teacher has warned parents not to put tracking devices on their children for school trips, claiming it is a “breach of privacy” for other pupils.

Ellen Taylor, of Whitstable and Seasalter Endowed CofE Primary School, sent out a letter after discovering the practice.

She says it has “never happened in previous years” but is a safeguarding risk, as it could reveal the location of other pupils to “prohibited persons”.

It comes as the use of small GPS trackers, which can cost less than £10, has been promoted on some social media accounts.

In a TikTok video watched almost 3 million times, a mum says she puts one of the devices in her daughter’s blazer for off-site activities.

But the Whitstable school - and bosses at Kent County Council - have advised against their use.

The letter from Ms Taylor says: “We have become aware of a situation that has never happened in previous years that we need to address with our families. Unfortunately, some parents have been attaching a digital tracker to their child for school trips.

“This is not permitted or appropriate and poses a safeguarding risk for the whole group.

“The use of digital tracking is a breach of privacy for the other children in the party.

“You may be unwittingly sharing information that may go against court orders or social services protection plans that you would most likely not be aware of.

“You may also be alerting prohibited persons to the specific live location of another child in the group which could potentially put the whole group at risk.”

Ms Taylor says she appreciates parents want to keep kids safe, but asks them to trust the school - which is rated outstanding - and its staff.

The letter continues: “We always take the recommended number of supervising adults and obviously our own school staff are all DBS checked and trained in keeping children safe and are known and trusted by them.

“They do not leave our supervision at any point, therefore minimising any risk of children going missing.

“In addition to this, any delay in return times is communicated with the school as well as directly with parents, if necessary.”

She calls the trackers “inappropriate and unnecessary”, as monitoring “every movement hinders a child’s freedom and spirit of adventure”.

“Whilst I fully understand that the use of tracking devices by parents has most likely been a well-meaning result of wanting to ensure your child’s safety and is tempting in today’s technology-driven society, I hope you can understand the reasons we have given for why we must insist that this does not happen again,” the letter sent on December 10 adds.

Small trackers are regularly advertised on TikTok. Some are mistakenly listed as GPS, but actually work via Bluetooth.

One video featuring a set was posted by user Three Good Reasons, who creates “honest reviews on top-quality products” on January 8.

In the clip, watched 2.7 million times, she says: “I’ve bought four of these so far and I’m probably going to get even more because they are under £10 and there’s so many ways to use them.”

She goes on to say she puts one in her car in case it gets stolen, one in her handbag and one on the dog’s collar, before adding: “And I’ve got a spare that I drop into my daughter’s blazer pocket when she goes on a school trip.”

Another video, posted in August by a different user, describes AirTags as a “back to school must have”.

Encouraging people to buy them, Naylen Ramirez says: “Sending your kids on school trips can be nerve-wracking.

“That’s why I use AirTags for peace of mind, always knowing where my child is.

“I bought two types of holders for it, one attaches to shoes with cute animal designs, and the other is a pin holder that clips to clothes, backpacks, strollers or any belongings.”

Another clip with 2.1 million views shows a parent tying a tracking watch into her daughter’s ponytail, with the caption: “When your baby goes on her first field trip.”

A Kent County Council spokesman said: “We would not expect trackers to be used for directly supervised visits, such as those carried out by primary schools.

“Teachers will have carried out risk assessments, and they are in direct control and have sight of their pupils during school trips."

Company Evolve Advice specialises in giving guidance to schools about class trips.

In one blog post, managing director Jake Wiid discussed whether the devices should be allowed.

He said: “Schools are under increasing pressure to allow or provide tracking devices when on educational visits.

“They present some risks to individual and group safety and concerns of an erosion of trust between parents and teachers. Their use should be carefully evaluated.

“There is no one-size-fits-all answer, but our advice to all settings is to assess the ethical implications and to find the right balance between safety and personal freedom for your specific situation.

“Schools should develop a clear policy on the use (or non-use) of tracking devices and communicate this clearly to staff, students and families.”

Ms Taylor declined to comment further.