Millions in the UK were tracked by their own phones without their knowledge after receiving a vaccine, a report claims.
Phone users were being tracked for a government study into how their movements changed after receiving a jab.
Data from one in ten people’s phones in Britain was tracked in February, scientists reportedly admitted.
Privacy campaigners branded it a “chilling” use of personal data.
According to The Telegraph, the cellphone data was used by researchers at Oxford University, who were carrying out studies for the Scientific Pandemic Influenza Group on Behaviours (SPI-B).
The group advises the Scientific Advisory Group for Emergencies (SAGE).
Oxford experts reportedly had access to cellphone mobility data for one in ten of the British population and were able to work out that 4,254 individuals had received a vaccine.
They then are said to have tracked the vaccinated group by using call data records and monitoring locations for the week before and after the individuals’ jabs, to see whether a change in movement could be detected.
The scientists were reportedly looking for evidence that behaviour changed after people received a vaccine dose.
By comparing the movements of the jabbed population they monitored against a control group the scientists found that their “average pre-vaccination mobility increased by 218 metres, the newspaper reported.
A government source told the newspaper that people were not tracked at an individual level, that the data was anonymised, and it was not possible for scientists to identify the people who were monitored.
They added that it was GPS tracing, and said the study was approved by an Oxford University ethics committee.
But Silkie Carlo, a spokesman for Big Brother Watch, told the Telegraph: “No one expects that by going to get a vaccine they will be tracked and monitored by their own Government.
“This is deeply chilling and could be extremely damaging to public trust in medical confidentiality.
“Between looming Covid passports and vaccine phone surveillance, this Government is turning Britain into a Big Brother state under the cover of Covid. This should be a wake up call to us all.”
A Government spokesman told the newspaper: “All the data sets used in this research are set out in the paper which makes clear that the mobile phone location data used is GDPR-compliant and has been provided from a company that collected, cleaned, and anonymised the data.
“The data is at cell tower rather than individual level and the researchers were granted access to the dataset under a research contract with ethical approval provided to the researchers from the University of Oxford, working on behalf of SPI-B”.